A new investigation shows that Vladimir Putin is "constantly" followed by a doctor who specialises in thyroid cancer. 

According to investigative media outlet Proekt, blocked by the Russian government and now operating from outside Russia, surgeon Yevgeny Selivanov, of Moscow's Central Clinical Hospital, has flown to see Putin at least 35 times in Black Sea resort Sochi, Putin's favourite place of residence. 

According to the report, a large group of doctors, including the thyroid cancer surgeon, accompanied Putin on his trips to his residence in the resort city of Sochi from 2016-2019. 

An average of five doctors had accompanied Putin in 2016-17 and nine doctors in 2019. 

"Over the course of Putin's 23-year rule, the country doesn't know a word of truth about the physical and emotional condition of the person ruling over it," Proekt editor-in-chief Roman Badanin said in a video posted online. 

"We can affirm that by his current presidential term, the Russian leader is not in good health," Badanin added. 

The investigation also claims Putin may have undergone surgery in November 2016 and that the specialists returned to treat "a likely relapse of his trauma" in late November 2019. 

"A serious manipulation is performed on a man with the nuclear button while we're told he's healthy," Badanin said. 

Proekt claims Putin's ill health is "the main secret of the Kremlin". 

The investigation details the various occasions on which ill-health appears to have interfered with Putin's activity as president of Russia. 

The report suggests Putin secretly underwent surgery last year, saying the president "did not appear in public for the entire month of September". 

"In medical circles, it is believed that the president was undergoing a complicated procedure related to some kind of thyroid disease during this period.". 

Proekt's investigation supports speculation that Putin has thyroid cancer and that steroids have been used in his treatment. 

Steroids would explain Putin's bloated face, which many have pointed out from photos and video of his recent appearances. 

Deer antler baths 

According to the report, Putin bathes in deer antlers as an alternative therapy. 

Sergei Shoigu, currently Russia's defence minister, is the one who introduced Putin to antler baths in the early 2000s. 

An extract is taken from the antlers of red deer, which are removed with a saw in springtime when the antlers are full of fresh blood. 

Clinics that sell antler baths claim the practice bestows various health benefits. According to a clinic in Siberia's Altai Mountains, the benefits of deer antler baths include "male potency". 

"An acquaintance of the president claims that he had been warned that there is no conclusive evidence of the benefits of antler baths. But Mr Putin liked it, and since then he has revisited Altai multiple times," the report says. 

According to the investigation, Putin is undergoing regular, stringent isolation because of his ill health. 

Referring to the infamous long table at which he hosted French president Emmanuel Macron, the report points out: "Putin has spent the Covid-19 pandemic in a way that no head of state in the world has ever done, the Russian president held most of his meetings via video link, and only allowed the few visitors to see him after a two-week quarantine and a stool test. 

"It was obvious that the leader's health was the number one priority," it adds. 

Kremlin spokesman Dmitry Peskov has denied the claims of Putin's ill health made by the report.