Former Trump campaign chairman Paul Manafort and his former business partner Rick Gates surrendered on Monday to Justice Department’s special counsel Robert Mueller after being indicted on charges of conspiracy against the US, money laundering and making false statements.

The two were indicted under seal on Friday. Mueller said Manafort laundered more than $18 million to buy properties and services, the New York Times reported.

“Manafort used his hidden overseas wealth to enjoy a lavish lifestyle in the US without paying taxes on that income,” the indictment read.

Gates was accused of transferring more than $3 million from offshore accounts. “As part of the scheme, Manafort and Gates repeatedly provided false information to financial bookkeepers, tax accountants and legal counsel, among others,” the indictment read.

The indictment against the two men contained 12 counts: Conspiracy against the US, conspiracy to launder money, unregistered agent of a foreign principal, false and misleading US Foreign Agents Registration Act (FARA) statements, false statements, and seven counts of failure to file reports of foreign bank and financial accounts.

The charges did not cover any activities related to the 2016 presidential campaign, though these are the first criminal allegations to come from Mueller’s investigation into possible coordination between the Trump campaign and Russia to influence the 2016 election.

Manafort arrived at the Federal Bureau of Investigation’s Washington field office on Monday morning. The two were being processed separately, according to a law enforcement official.

They will later be transported to federal district court in Washington and will make their initial court appearances before US District Magistrate Judge Deborah Robinson.

A White House spokesman told CNN that the Trump administration “may not have a response at all” regarding the charges.

Manafort, whose work for former Ukrainian President Viktor Yanukovych attracted scrutiny from federal investigators, previously denied financial wrongdoing regarding his Ukraine-related payments, his bank accounts in offshore tax shelters and his various real-estate transactions over the years.

He joined the Trump campaign in March 2016 and Trump tapped him to serve as campaign chairman in May of that year. Manafort left in August 2016 after being accused over his dealings with pro-Russian politicians in Ukraine.

Gates, who also denied wrongdoing, was Manafort’s longtime business associate in his lobbying firm before being tapped as his deputy on the Trump campaign.

Over the weekend, the US President called Mueller’s investigation a “witch hunt” and demanded that “something” be done about alleged irregularities that his former Democratic presidential rival, Hillary Clinton, committed during the 2016 election.