Following the reports earlier this week about the non-confirmation of the cause of Viktor Yuschenko’s illness, he has now returned to the hospital in Austria this weekend for a series of further tests that will try and assess the cause of it.

At the clinic in Vienna, doctors will carry out tissue biopsies, including tests on Mr Yushchenko’s skin.

“It will be an entire imaging diagnosis to look at the size and function of his various organs. We are going to reassess the entire blood chemistry, including possible types of poisoning,” said Dr Michael Zimpfer, director of the Rudolfinerhaus hospital.