MOSCOW (Reuters) – A Russian court on Saturday ordered Michael Calvey, the U.S. founder of one of Russia’s biggest private equity firms accused of fraud, to be kept in custody until April 13.

Calvey, a senior partner at Baring Vostok and among Russia’s most prominent investors, was detained on Thursday along with other executives after investigators accused them of embezzling 2.5 billion roubles ($37.73 million). Calvey denies the accusations.

On Friday, Moscow’s Basmanny court ordered Calvey to be detained for 72 hours, but said the court would consider on Saturday if he should continue to be kept in custody.

Judge Artur Karpov extended the custody until April 13 after listening to the prosecutors, Calvey’s lawyers and Calvey himself at Saturday’s hearing. A U.S. embassy official was present.

Explaining his decision, the judge said that Calvey was accused of a “serious” crime and could try to flee.

Baring Vostok has over $3.7 billion of committed capital, according to its website. It has stakes in a number of Russian companies from online video services to internet and cable TV providers.

The company was also an investor in Yandex, now Russia’s biggest internet search engine, during its build-up. Yandex, also known as ‘Russia’s Google’, currently has a market capitalisation of $10.3 billion.

Prosecutors said on Friday that Calvey and other executives at his fund were suspected of embezzling the money by persuading shareholders in a Russian bank to accept a stake in another firm at an inflated price.

The alleged scam occurred in 2017 and involved Vostochny Bank, a mid-sized lender in which Baring Vostok has a controlling stake. It concerned the transfer of equity in Luxembourg-based International Financial Technology Group.

Calvey, speaking calmly from a locked glass-walled space inside the court room on Saturday, repeated he disagreed with prosecutor’s asset valuation but said he was “ready to cooperate with the investigation”.

“I’m not going to run,” he told the court via his lawyer who translated his speech into Russian.

The judge asked the prosecutors to bring a document from the Russian central bank to support their 2.5 billion rouble estimate of the alleged fraud.

Russian President Vladimir Putin was informed of the detention, Kremlin spokesman Dmitry Peskov was quoted as saying by RIA news agency late on Friday.

Lending support to Calvey by issuing written statements on Saturday were Kirill Dmitriev, the head of Russia’s sovereign wealth fund, and German Gref, head of Sberbank, Russia’s biggest state bank.

Calvey’s lawyer, Dmitry Kletochkin, told reporters after the decision that his client was innocent. Russian news agencies reported separately that Calvey would appeal the decision.