Two companies in the Channel Islands are escaping UK controls on the sale of impotence wonder drug Viagra and selling it via mail order around the world.

The BBC's Clinton Rogers on offshore Viagra

The firms, who can operate legally because they are based offshore, say the business is perfectly ethical.

Tom O'Brien of Direct Response Marketing says that people buying the drug have to fill in a health questionnaire.

He says that, as long as they are being honest, he can see "no problem with ethics at all".

No health checks

But health officials are worried. They say there are no health checks to ensure people for whom the drug could be dangerous are not ordering it.

Pfizer, Viagra's manufacturer, warns against people taking the drug if they are on any nitrate-based preparations.

There are also concerns about people with heart conditions taking Viagra, following the deaths of a number of heart patients who have popped the little blue pill.

Richard Grainger, a Jersey medical officer, said: "Viagra is a very powerful drug and people who are going to use it need to be adequately assessed.

"We have a general concern about the sale of pharmaceuticals via mail order and the internet."

Temporary block

The Department of Health has put a temporary block on prescription of Viagra on the NHS because of concerns about its cost due to its popularity.

Tom Frewen: government is promoting the black market in Viagra

It can only be prescribed on the NHS in exceptional circumstances, although it can be sold privately.

Doctors say the "grey trade" in Viagra, such as the sale of the drug through the internet, has been fuelled by the Department's attitude.

Tom Frewen of the British Medical Association says doctors are not being told what the exceptional circumstances are in which it can be prescribed on the NHS.

"The very nature of what the Department of Health has done has caused this black trade," he said.

But the Department of Health said the trade had been going on since before it issued its temporary guidance on Viagra after it was licensed in September.