Africa: One of the world's largest pharmaceutical companies is to dye anti-Aids drugs on sale in developing countries in order to prevent subsidised pills being smuggled back into Europe and sold at inflated prices.
Packaging is also to be redesigned to make it easier to track shipments.
Andrew Bulloch, managing director of GlaxoSmithKline east Africa, said the move came amid growing evidence that criminal syndicates were involved in a smuggling racket worth millions of euro.
"This has been going on since the price of anti-retrovirals began falling in the developing world, and the differential with the developed world began widening, increasing the temptation for smugglers," he said.
"All the anti-retrovirals that we will be supplying into the developing world through our access programmes will now be colour-differentiated from what is being sold in Europe and north America.
"The packs will be different, as will the actual physical appearance of the tablets or capsules."
A United Nations-funded programme allows drugs companies to sell anti-Aids therapies to the developing world at reduced prices. It means a month's supply of Combivir, one of GSK's anti-retroviral drugs, costs about $20 (€15) in east Africa. The same drug sells for more than $600 (€449) in Europe.
GSK says it is investigating several cases of smuggling and expects court action to be launched later this year.
The anti-smuggling alterations have already been approved in Kenya, Tanzania, Uganda, Ethiopia and Sierra Leone and come at a time when African nations are stepping up the fight against HIV.
The World Health Organisation has set a target of treating three million patients with the anti-retroviral drugs by the end of the year.
However, the target represents a drop in Africa's HIV ocean. Almost 30 million people are estimated to be infected with the virus on the continent.