Russian President Vladimir Putin, 69, is said to be suffering from a brain disorder caused by dementia or Parkinson’s disease resulting from steroid treatment for cancer.

In recent videos and photos, Putin has appeared notably more bloated around the face and neck.

Some of the senior figures from Canada, Australia, New Zealand, the UK and the US believe that there is a physiological explanation for his decision to invade Ukraine, reported Daily Mail.

Mirror reported citing sources close to the Kremlin, the senior figures are investigating reports that Putin’s “increasingly erratic behavior” combined with a bloated appearance point to usage of drugs.

Only human sources can "offer you the sort of rich picture that we have of Putin’s psyche," a source said. The insider added that "there has been an identifiable change in his decision-making over the past five years or so." The source said that those around Putin see a "marked change in the cogency and clarity of what he says and how he perceives the world around him." The insider shared that this failure to think clearly was being compounded by the lack of a "negative feedback loop," with Putin "simply not being briefed" on elements of failures with the invasion.

Putin reportedly blamed his deputy, Anatoly Bolyukh, and Sergey Beseda, the head of the FSB’s foreign service, for intelligence failings that saw his army handed a series of defeats in Ukraine. Following this he had reportedly placed the two under house arrest.

Putin has suffered a psychological deterioration caused by physiological factors, suggested the intelligence. According to theories, he is either suffering from a brain condition, such as Parkinson’s disease or a more generic form of dementia. The other theory is that he might be suffering from cancer and the medical treatment he is receiving to battle the disease has altered his mind's balance. The last theory is that the mental deterioration is the result of "roid rage" which is caused by the prolonged use of steroids.

Putin’s decision to physically isolate himself from guests is a sign of a fear of "co-morbidities" or the use of drugs which suppress the immune system, leaving him open to infections, according to sources.

Last month when Putin and Emmanuel Macron met, the French president was made to sit at the other end of a long table. Also, many of those entering his presence have been asked to quarantine in hotels for two weeks beforehand.

A giant figure representing Russian President Vladimir Putin A giant figure representing Russian President Vladimir Putin swallowing a map of the Ukraine is seen during a demonstration against Russia's invasion of the Ukraine, on March 13, 2022 in Berlin. - The figure was created by French carnival float constructor Jacques Tilly and in Duesseldorf, western Germany, during a Rose Monday event in this carnival hotspot. The lettering reads: "Choke on it!!!". Photo by John MacDougall/AFP via Getty Images