Special Counsel Robert Mueller wants to know more about a US$1 million loan made to Paul Manafort’s family in the days after the FBI raided his home.

Mueller’s prosecutors on Thursday told a court they needed to know more about the August 2017 loan, from a Nevada company called Woodlawn LLC. Manafort, the onetime chairman of President Donald Trump’s campaign, guaranteed the loan, which was secured by the family’s interest in a Manhattan condominium, according to court papers.

As Manafort’s legal problems escalated, Woodlawn installed a Hollywood bit player named Joey Rappa as its “managing member” in public filings. The investor or investors funding the loan wanted to remain anonymous given the potential for embarrassment, according to a lawyer for the lender.

Now that prosecutors are seeking to seize the condo after Manafort’s conviction on tax- and bank-fraud charges, Woodlawn is staking a claim to it in order to collect on the debt.

But one riddle remains: Who actually funded the US$1 million loan?

Prosecutors said “additional information and evidence will be necessary to evaluate the nature and extent of Woodlawn’s claims” before the U.S. resolves the firm’s request.

Woodlawn’s lawyer declined to comment.

Mueller is investigating Russia’s effort to boost Trump over Hillary Clinton in the 2016 presidential election and any ties between that interference and the Trump campaign.

Meanwhile, prosecutors are wrapping up deals on claims by some other Manafort creditors, including the condo board of Trump Tower, where Manafort and his wife owned an apartment that prosecutors are also seeking to seize.