The purchase of surgical equipment should be bound by the same fair trade rules as foodstuffs like coffee, sugar or bananas, a researcher suggests.
The NHS does have a policy suppliers should conform to trade standards
Dr Mahmood Bhutta said he had anecdotal evidence there was exploitation of workers in developing countries.
In the British Medical Journal, the ear, nose and throat doctor said it was down to purchasers such as the NHS to press for fair trade.
The Department of Health said buying equipment was down to NHS trusts.
But Dr Bhutta said no systematic investigation had been undertaken into the sourcing of healthcare goods from developing countries.
Pakistan and Malaysia are centres for surgical instrument manufacturing.
Dr Bhutta, whose family comes from the Sialkot area of Pakistan - a centre for instrument making - has interviewed a number of workers and focussed on issues relating to global health and medical ethics.
He wrote in the BMJ: "When surgical instruments have come from manufacturers in the developing world then, as is the case with other goods, the trade may be open to the exploitation of power by transnational companies, driving down prices and labour standards."
The global trade in hand-held stainless steel surgical instruments was worth at least £352m a year, he added.
In developing countries, much of the early stage of manufacture - forging, filing, grinding - is subcontracted out to workers employed in a small workshop or their own home.
Manual labourers are paid per instrument, and Dr Bhutta said workers often earn just $2 a day, with no job security, medical insurance or education for their children.
He highlighted past research which has shown many subcontracted workers in developing countries are children.
Only finishing and quality checks are carried out by companies in-house.
Dr Bhutta added: "When these goods have come from manufacturers in the developing world then, as is the case with other goods, this trade may be open to the exploitation of power by transnational companies, driving down prices and labour standards.
"The scale of such abuse is difficult to ascertain, because we usually do not know or do not ask where our healthcare products are manufactured or sourced.
"The trade in surgical instruments is open to unethical sourcing because many such instruments are manufactured in the developing world.
"This is rarely brought to the attention of end purchasers and consumers."
He added: "The solution lies in purchasers insisting on fair and ethical trade when sourcing instruments.
"Pressure must be applied to suppliers in the developing world to be transparent about where their instruments have been manufactured and for them to ensure that the labourers have been paid a fair wage and that international labour and health and safety standards have been followed."
He said the NHS Purchasing and Supply Agency had developed a sustainable development policy, part of which encourages NHS suppliers to ensure compliance with international labour standards.
But he said there was no systematic assessment of products' origins or production conditions.
A spokesman for the Department of Health said: "The purchasing of equipment is a matter for individual trusts."