Doctors have failed to diagnose former Russian Prime Minister Yegor Gaidar’s mysterious illness, saying they suspected poisoning, but were unable to detect the toxic substance that could be to blame, an aide said today.

The Government should launch emergency radioactivity tests at all the sites visited by former Russian prime minister Yegor Gaidar, the Green Party said today.

Doctors treating former Russian prime minister Yegor Gaidar, who is gravely ill, believe he was poisoned, an aide said today.