Russian  opposition politician Alexei Navalny‘s doctor Anastasia  Vasilyeva (43) said to AFP he was “not allergic to anything”. (Image: archive)

“It was a toxic reaction to a chemical, it was definitely some chemical agent,” she said. “It’s absurd to call it an allergy.”

According to  Vasilyeva, Navalny “needs to be under close medical supervision”, and should be allowed to call his relatives.

Kateryna Yushchenko, the former Ukrainian first lady whose husband Viktor Yushchenko was poisoned 15 years ago, wrote in her Twitter micro blog:

“This brings back horrific memories of September 2004. Our doctors also balked at diagnosing what happened to my husband as poison. And some doctors with security pasts tried to cover it up. Recommend Alexei get treatment in Europe ASAP.”

There’s been no evidence that Mr Navalny was poisoned. But his doctors – and his supporters – are keen to know what sparked such sudden symptoms.

Two years ago Alexei Navalny was the victim of an assault. He suffered a chemical burn in his right eye after someone threw green-coloured antiseptic in his face.

The personal doctor said the jailed Russian opposition leader was discharged from a Moscow hospital after a possible exposure to an unidentified “toxic agent“, while health officials insisted his condition was satisfactory.

Anastasia Vasilyeva-told Russia’s Dozhd broadcaster that Navalny was returned to the prison on July 29.

“We cannot rule out that toxic damage to the skin and mucous membranes by an unknown chemical substance was inflicted with the help of a ‘third party‘,” Vasilyeva  wrote on Facebook page.