A search warrant application unsealed Wednesday revealed President Trump’s former campaign manager Paul Manafort received a $10 million loan from a Russian oligarch.

An FBI agent said he had reviewed tax returns for a company controlled by Mr. Manafort and his wife that detailed the loan from Oleg Deripaska, who has close ties to the Kremlin, according to an affidavit attached to the July 2017 application.

The loan shows that Mr. Manafort may have had closer links that previously known to Mr. Deripaska. Special counsel Robert Mueller has been investigating ties between the two as part of his probe into possible Russian collusion with the Trump campaign.

A metals magnate, Mr. Deripaska was among the Russian oligarchs sanctioned by the United states in April.

The affidavit also disclosed that Mr. Deripaska had financially supported Mr. Manafort’s Ukrainian consulting business when it started in 2006. It also confirmed that Mr. Muller is looking at Mr. Manafort’s role in a July 2016 Trump Tower meeting with a Russian lawyer.

FBI agents used the warrant to raid Mr. Manafort’s home in July 2017.

The search warrant showed the FBI sought “communications, records, documents and other files involving any of the attendees of the June 9, 2016 meeting at Trump Tower, as well as Aras and Amin Agalarov.” The warrant misspelled the first name of Emin Agalarov.

Aras Agalarov is also a Russian oligarch with ties to the government and his son, Emin, is a singer.

The search warrant was unsealed one day after a federal judge in Virginia declined to dismiss the charges Mr. Manafort faces there. Mr. Manafort also headed to trial in Washington, D.C. later this year.

Prosecutors have charged Mr. Manafort with a host of crimes, including money laundering, tax evasion, making false statements to investigators and failing to register as a federal agent.

Mr. Manafort has pleaded not guilty and denied the accusations.