Oleg Tinkov, former owner of the Tinkoff Saxo team that includes Peter Sagan and Alberto Contador, has posted £20 million bail to avoid jail time due to remand after a provisional arrest warrant was issued by US prosecutors.

According to reports in the UK and major financial media, the 52-year-old Russian billionaire made his first appearance before a Westminster magistrate last week, accused by the US Internal Revenue Service (IRS) of filing false tax returns in 2013 for underreporting his income as a US citizen. The hearing is expected to last until April.

Tinkoff paid 20 million pounds and was allowed to stay in a luxury apartment owned by his wife in central London as long as he observed a 7 p.m. to 7 a.m. curfew. He is also barred from entering the airport and must stay within the M25 freeway that surrounds London. He must surrender his passport and must report to the police three times a week.

Tinkoff has set up and sold a series of businesses in electronics, pasta, beer, and most recently banking, reportedly worth £2.2 billion. The online Tinkoff Bank now has about 8 million customers in Russia, and Tinkoff has listed the bank on the British stock market.

An avid cyclist, Tinkoff honed his entrepreneurial skills by racing in Russia as a junior, buying jeans at training camps in the Ukraine, and selling them at home in Siberia for a profit.

His first cycling team sponsorship came in 2005 when he founded the professional continental team Tinkoff Restaurants. Tinkoff ended its sponsorship in 2008, but returned to the sport in 2012 and acquired the Saxo Bank team from Bjarne Riis in December 2013.

Alberto Contador won the 2014 Vuelta a España and 2015 Giro d'Italia with this team, and Peter Sagan took multiple green jerseys at the Tour de France. However, the team failed to overturn Team Sky's dominance in the Tour de France, and Tinkoff was often publicly annoyed; he eventually quit the sport after the 2016 season, giving a final interview to Cycling News.

Tinkoff reportedly offered Dave Brailsford £17 million to take over Team Sky when the British team was looking for a new sponsor, but Ineos stepped in to save the team.

Shares in TCS Group Holding Plc, a Tinkoff subsidiary, fell 6% on Monday when news of the trial broke; TCS Group Holding issued a statement saying, "Mr. Tinkoff is attending the trial in his personal capacity and this situation is not affect any of Tinkoff Group's operating companies, including Tinkoff Bank, Tinkoff Insurance, or Tinkoff Mobile."

According to the Sunday Express, the IRS sued Tinkoff for filing false tax returns and underreporting income for 2013. Tinkoff returned his U.S. passport in 2013 and sold most of his company's shares on the London Stock Exchange that same year.

U.S. passport holders must pay an "exit tax" to the IRS when they renounce their U.S. citizenship. This tax is based on the gain from the sale of all assets at the time Tinkoff renounced his citizenship; when Tinkoff renounced his U.S. citizenship in 2013, the maximum income tax rate was 39.6%, while the Russian income tax rate was a flat 13%.