Two French twin brothers who became the faces of a famed 1980s science TV programme before winning notoriety for their cosmetic surgery have died within a week of each other from Covid-19 after refusing the vaccination, friends and family said.

The death of Igor Bogdanoff, 72, was confirmed on Monday evening by his lawyer Edouard de Lamaze, as well as his agent.

He died just six days after his brother Grichka Bogdanoff passed away in a Parisian hospital, also of Covid, the lawyer confirmed.

Instantly recognisable in France and a favourite in the country's glossy celebrity magazines, they also claimed to have taken part in the creation of Bitcoin.

"We were implicated, very early, in the birth of the cryptocurrency," Grichka told French TV show Non-Stop People in June, with their claim largely based on their friendship with Japanese mathematicians behind the currency.

The brothers became well-known in international cryptocurrency circles and a subject of mockery, largely thanks to an online meme and conspiracy theory that they controlled the markets.

Igor announced earlier this year that they planned to launch their own currency, "Exocoin".

Anti-Vax?

Neither of the brothers had been vaccinated against Covid-19, their friend Luc Ferry, a former education minister, said last week.

Ferry told Le Parisien newspaper that he had urged both of them to get vaccinated "countless times" but they refused on the basis that they were "very sporty, without a gram of fat".

"Grichka, like Igor, wasn't an anti-vaxxer. He was anti-vax for himself," Ferry said, confirming that both of them had contracted Covid. "I told them that it was grotesque, they were mad!"

In an interview at the beginning of December, they raised doubts about the new generation mRNA messenger vaccines developed by BioNtech/Pfizer among others, despite their approval by health authorities.

France is currently facing another major wave of Covid-19 infections caused by the highly infectious Omicron variant, with hospitals warning that intensive care units are overwhelmed with mostly unvaccinated patients.

Plastic surgery

The identical twins shot to fame as the heartthrob presenters of the hit 1980s science show "Temps X" on the country's TF1 channel and then carved out careers as amateur and often controversial science writers afterwards.

Born to a Russian-origin father, a painter, and an Austrian aristocratic mother, they grew up in a castle in southwest France.

"At the age of 11, we underwent tests which showed that we were part of 0.01 percent of the population with an IQ of more than 190," Grichka once claimed, feeding the mystique of the twins as freakishly intelligent.

Critics would accuse them of plagiarising the work of others, and of promoting pseudo-science in their subsequent publications and media interviews.

Igor married several times to aristocratic French women, fathering six children, while Gricha remained single, one of few differences between the two men who would often finish each other's sentences during interviews.

In their later years, their looks, socialite lifestyle and legal problems stemming from their attempt to relaunch "Temps X" kept them in the public eye.

They faced prosecution for allegedly cheating a millionaire with mental health problems out of several hundred thousand euros -- charges they denied.

They also denied having plastic surgery to explain their transformed looks, but admitted to having undergone "experimentations" which gave them their extreme high cheek bones, as well as large lips and pronounced chins.

"We are proud of having faces like extra-terrestrials," they said in 2010.