Doctors' leaders have strongly criticised the continuing reliance on medical staff from developing countries to fill NHS vacancies.
Africa's health workers are deserting the continent's poorer countries
British Medical Association chairman James Johnson said taking much-needed staff is morally indefensible.
The BMA says African nations in particular are being damaged.
The government's tougher code to prevent the active recruitment of such workers does not stop those who volunteer to come to the UK, it says.
Last year two thirds of newly-registered doctors, and more than 40% of nurses, came from abroad.
About 12,500 doctors currently registered to work in Britain are from African nations that face serious staff shortages themselves, said the BBC's Mike Thompson.
And, over the last six years, nearly 16,000 African nurses have registered to work in the UK.
In Zambia only 50 out of 600 doctors trained since independence are still practising in the country.
Three-quarters of Zimbabwe's doctors have left since the early 1990s.
More than half of all Ghana's doctors have left the country and a quarter of Malawi's remaining health workers are expected to die from Aids within five years.
In Uganda there are only 10 nurses for every 100,000 people - 10 times less than in the UK.
The government recently introduced a tougher code of practice to stop the active recruitment of the developing world's health workers.
But the BMA says this move does not stop those who volunteer to come to Britain in search of better salaries and conditions.
According to new figures obtained by the BBC, it costs African nations £270m to train the doctors and nurses who have migrated to Britain, said our correspondent.
The same statistics also show that Britain, where training is much more expensive, has saved 10 times that by not having to school them itself. This is what the BMA insists cannot be justified.
James Johnson, BMA chairman, said: "If you go to a country like Ghana, which has a population of about a third of ours, they have 1,500 doctors in the whole country.
"It is just astonishing. There is literally, in some parts of these countries, no healthcare of any sort."
Mr Johnson said it was vital the government committed itself to becoming self-sufficient in doctors and nurses within the next decade.
"If one considers the absolutely catastrophic effect that the current polices are having on the developing world, it seems quite immoral to consider any other course of action."
The Department of Health said that over the last five years Britain had donated £560m towards healthcare in Africa.
A spokesman said: "The NHS does not actively recruit from any country that does not wish to be recruited from.
"The NHS leads the way in the ethical recruitment of healthcare professionals with a strict list of countries from which it does not actively recruit, drawn up with the agreement of the countries involved, which includes much of Africa.
"However, if healthcare professionals are determined to come here to work we cannot legally deny them that opportunity."
Shadow Health Secretary Andrew Lansley said: "We have committed ourselves to training more doctors.
"It is not sustainable for Britain to drain developing countries of doctors and nurses vital to the development of their own health services."
Liberal Democrat health spokesman Paul Burstow said: "The NHS has been far too dependent for far too long on overseas recruitment.
"Despite the protestations of Ministers that we have the most ethical policy in the world, that policy is neither monitored nor enforced." systems of essential staff."
Tom Hadley, of the Recruitment and Employment Confederation, said the issue was complex.
"Restricting international opportunities for healthcare workers could make the profession less attractive to those in developing countries which could lead to skills shortages.
"In addition, the vast majority of those who come to work in the UK from developing countries currently return to their country of origin after a few months or years, often with vastly improved skills and levels of experience.
"The concern is that if seeking employment in the UK is made more difficult, they will simply go to other countries, such as Australia and the US, where the process of finding work is not hampered."
Here are a selection of your views
The ethics of governmental finances and politics leave me cold at the utter callous indifference to populations and infrastructures in the developing world; arms for profit, aid to corrupt dictatorships, plundering of human resources.
The public health consequences of survivalist migrations, compounded by irresponsible individual practices, will lead directly to the exploitative nations reaping the aftermath of their short-sighted greed.
Dr Wassim Malas, Manchester - United Kingdom
The problem lies with the countries where these doctors originate, not the opportunities awaiting them elsewhere. It is naïve to believe that the domestic situation of their countries of origin does not affect their intent to migrate.
Under apartheid, South Africa experienced a brain drain too. The solution to reduce this outflow was to end apartheid, not prevent the emigrants from leaving by blocking their entry to other countries.
By sorting out the real problems in countries like Zimbabwe you may find doctors willing to stay there. These always reflect back to their leadership.
Glenn Lewis, Amsterdam, Netherlands
It is scandalous that we take doctors and other medical staff from Third World countries, instead of training our own. At the age of 29, having worked overseas, and saved most of my earnings, I applied for a University place to study medicine.
As I was financially secure, and able to pay for the course, I offered to do so. The powers that be, however informed me, that I was too old to start a medical course. With this sort of attitude, it is no wonder we are short of 'home grown' doctors.
Paul M, Huddersfield
The head of the British Medical Association is effectively complaining that people living in poverty take the difficult decision to leave behind their relatives and friends to go search for better working conditions and salaries that would guarantee a better future for their dependents.
Members of the BMA would definitely do the same if they ever lived in the poverty experienced by African doctors and nurses.
It would be good if those righteous took the time to consider that those doctors and nurses are human beings, some with families, who would gladly stay with old friends and relatives in Africa if only they could earn what counterparts in Europe earn.
Piu Neville, Dar es Salaam, Tanzania
Those health care workers that can, will consider to move to where they can work and live under easier circumstances.
We don't really see Australians or Britons or French or Germans etc, leaving their countries in hordes?
It is due to "pushing factors" rather than "pulling" that cause people to leave in masses.
I have gone both ways and the decision is never easy. Africa needs to start using the billions in aid money received n a constructive way.
Dirk von Delft, Cape Town, South Africa (again)
If you work in a country where the government would hold your salary for months then you would understand why the doctors have to leave , the reason is simple the government in most African countries are irresponsible to the needs of the people.
Andy Esun, Warri , Nigeria
African governments need to value us doctors. I have doctor friends working in Ghana and when you start working after medical school you could work for over 4 to 6 months before you are paid. Also you don't officially have a single day off.
Doctors are badly paid in general. Also, if you training outside and go back home, they make it very difficult for you to stay.
I have heard of consultants from the US who wanted to go back to Ghana but they were treated in such a way they had to leave Ghana. Africa can gain from the training doctors receive if the health system opens up to receive us. Until then, I'm afraid people like myself will sadly remain in the UK.
James, Reading. UK
Would it be better if medical personnel from so called "developing" countries were forced to work for a government that refuses to pay their salaries for several months, equip the hospitals and promote research?
What quality of health care would be obtainable in a system like this ? The solution is to ensure good governance in these countries.
Medical personnel are human too, they have a right to the basic needs of life which they are currently being denied in the so called "developing" countries.
Oyin Oyatoye, Nigeria
To blame the problems of Africa's health crisis on the NHS is ludicrous. The issue is simple, after studying for many years African doctors take the economic decision to work in the West where health standards, facilities and quality of living are far higher than anything Africa can offer.
Of course there a small minority of African doctors who genuinely want to help their fellow people however it is the responsibility of African governments to improve levels of healthcare and doctors' welfare.
Farooq, Manchester, UK
This is deja vu for many of us who grew up in Africa and we were strongly committed to stay and help develop our various countries.
Having lectured in my home country, Sierra Leone for several years the situation became untenable. Salaries, working conditions, political thuggery and the manipulation of the constitution drove many of us out of the country. For those of our friends and relatives that stayed at home,11 years civil war compounded their problems.
I know a good number of people in my situation who are quite willing to go back and help provided, the level of corruption and mismanagement can be reduced.
It seems that the brain drain has a direct co-relation to the level of corruption and on under development that prevails in a country. One only needs to look at certain countries in West Africa.
Professor Kingsley Banya, Miami Florida USA
This situation is ridiculous. I know of so many friends who desperately tried to get onto medicine courses with 3 A's at A-level but got turned down due to lack of course places.
There are quite clearly enough people in this country who want to be doctors yet the government fails to create more courses.
It's then so insulting to those who've worked their socks off at A-level to see foreign doctors being imported.
If more courses were made available then more doctors would be trained, thus solving the shortage problems. I can't see why the government hasn't got this sorted, it's not exactly rocket science is it?
Anon, Reading, UK
Why are we pushing the blame on the west? Neither UK nor US or Canada is responsible for the migration of doctors from Africa.
Every human being regardless of race, tribe or ethnicity need the same basic necessities for life; food, security and decent shelter to live. All these are lacking in Africa except for the politicians.
Thus ask the leaders who have failed their people. Afterwards brain-drain is far more better than brain-wastage.
I'm African living in the US and I'm in the health field, yet I have no intention to go Africa and work. I will go there to do some volunteer work to help my people if need be but not to stay there to work. Who will pay me?
Maada Jusu, Philadelphia, USA