Oleg Tinkov has been diagnosed with leukaemia.
The Russian business and former cycling team boss is currently in London while awaiting an extradition trial to the United States over allegations of tax fraud.
>> Struggling to get to the shops? Try 5 issues of Cycling Weekly magazine for just £5 delivered to your door <<
But Tinkov has released a statement explaining why he has not appeared in public in recent days, saying he has been diagnosed with an acute form of the cancer.
In a statement reported by Russian news outlet Vedomosti, Tinkov said: ““In recent days, I did not appear in public, which caused some questions and speculation, especially in light of the fact that the trial is on-going. And although I didn’t want to disclose the details for a long time, it seems that the time has come to inform you that I have been diagnosed with an acute form of leukaemia.”
Tinkov is a familiar name in cycling circles because of his years as a team owner.
The 52-year-old billionare bought the Saxo Bank team from Bjarne Riis in December 2013 and was often a divisive figure in the sport.
In 2016 he announce he would be leaving cycling sponsorship and his team was wrapped up in that November, having won the Vuelta a España with Alberto Contador and racking up numerous wins with Peter Sagan.
In February, Tinkov appeared at Westminster Magistrates’ Court after a provisional warrant for his arrest was issued by American prosecutors.
He is accused of filing a false tax return on which he under-reported his income in 2013.
The court set his bail at £20 million and his bail terms include a strict curfew until his next court hearing, where he will be electronically monitored and have to remain in his £7 million Kensington flat from 7pm until 7am every night.
Tinkov is also currently banned from airports and has to stay within the M25, having surrendered his passports and being under instruction to report to police three times a week.
Tinkov’s umbrella company, TCS Group Holding Plc, made a statement on the situation, saying he “is confident [the matter] will be resolved as swiftly as possible” before adding it “does not affect any of the operating companies within the Tinkoff Group”.
The billionaire is reported to be worth £1.9 billion, having launched his online Tinkoff Bank in 2006, which now has around eight million customers in Russia.