Malaria fight 'badly compromised' by resistance
6 April 2012 Last updated at 06:38 BST
Scientists have found new evidence that resistance to the front-line treatments for malaria is increasing.
They have confirmed that resistant strains of the malaria parasite on the border between Thailand and Burma, 500 miles (800km) away from previous sites.
Researchers say that the rise of resistance means the effort to eliminate malaria is "seriously compromised".
The details have been published in The Lancet medical journal.
Wendy Urquhart reports.