Independent US presidential candidate Robert F Kennedy Jr has revealed that a worm ate part of his brain.

It has emerged the 70-year-old made the claim during a 2012 interview, known as a deposition, in his divorce proceedings from his second wife Mary Richardson Kennedy. At the time, he said his earning power had been diminished by cognitive issues.

He said he had been having memory loss and mental fogginess in 2010 and so contacted neurologists who spotted a dark spot on his brain scans. They said he had a tumour but another doctor reached a different conclusion, believing he had a dead parasite in his head, The New York Times reported.

In his 2012 interview, Mr Kennedy said the medic thought that the abnormality "was caused by a worm that got into my brain and ate a portion of it and then died". Mr Kennedy, who is a son of former US attorney general and ex-senator Robert F Kennedy, and nephew of former US president John F Kennedy and ex-senator Ted Kennedy, also said during the deposition that he was diagnosed with mercury poisoning.

He said: "I have cognitive problems, clearly. I have short-term memory loss, and I have longer-term memory loss that affects me." He told The New York Times he was certain the mercury poisoning was caused by his diet that included lots of tuna.

Tuna contains higher levels of mercury than other fish, according to the NHS. Environmental lawyer and anti-vaccine activist Mr Kennedy, who is also known by his initials RFK Jr, told the publication: "I loved tuna fish sandwiches.

I ate them all the time." He said that tests showed his mercury levels were 10 times higher than what the Environmental Protection Agency sees as safe. A chemist told the same publication that the mercury levels which Mr Kennedy described were high but not surprising for someone consuming that quantity and type of seafood.

Mr Kennedy said he made changes after the health scares, including getting more sleep and cutting down on his fish intake. He told the paper that he had now recovered from the memory loss and fogginess and had no after-effects from the parasite, which he claimed had not needed any treatment.

Doctors who have treated parasitic infections and mercury poisoning have said both conditions can sometimes permanently damage brain function, but patients also can have temporary symptoms and mount a full recovery, the publication reported. Mr Kennedy said he did not know what type of parasite it was or where he may have contracted it.

But several infectious disease experts and neurosurgeons told The New York Times that based on what Mr Kennedy described, they believed it was likely a pork tapeworm larva. Read more from Sky News:Biden's dog 'should be put down'Biden 'happy to debate' TrumpWhat Truss and Trump have in common When asked if his health issues would impact his fitness to serve as president, a spokesperson for the Kennedy campaign told the publication: "That is a hilarious suggestion, given the competition." Mr Kennedy, along with two other third party candidates, philosopher Cornel West, 70, and physician Jill Stein, 73, face Democrat incumbent Joe Biden, 81, and Republican candidate Donald Trump, 77, in November's presidential race.

In the national polls, Mr Kennedy is currently on about 10%, compared with 41% for Mr Trump and 40% for Mr Biden..