US treasury department agents have obtained information about offshore financial transactions involving President Donald Trump's former campaign chairman as part of a federal anti-corruption probe into his work in Eastern Europe.
Information about Paul Manafort's transactions was turned over earlier this year to US agents working in the treasury department's financial crimes enforcement network, The Associated Press has learned.
Mr Manafort was Mr Trump's unpaid campaign chairman from March until August last year.
He has been a leading focus of the US government's investigation into whether Trump associates co-ordinated with Moscow to meddle in the 2016 campaign.
Records show Mr Manafort was known to route financial transactions through Cyprus.
A spokesman for Mr Manafort did not immediately respond to questions.
Earlier this week, it emerged that Mr Manafort carried out secret work for a Russian billionaire to advance the interests of Russian president Vladimir Putin a decade ago.
Federal prosecutors became interested in Mr Manafort's activities years ago as part of a broad investigation to recover stolen Ukrainian assets after the ousting of pro-Russian president Viktor Yanukovych there in early 2014.
No US criminal charges have ever been filed in the case.
It is not immediately clear what time period was covered under the government request for information about Mr Manafort's financial transactions in Cyprus.
He was known to have routed financial transactions through Cyprus, according to records of international wire transfers obtained by the AP and public court documents filed in a 2014 legal dispute in the Cayman Islands.
In the 2014 case, Mr Manafort used Cypriot shell companies as part of a 19 million dollar deal with Russian billionaire Oleg Deripaska to purchase Ukrainian cable television provider Black Sea Cable.
Mr Deripaska said that after taking the money, Mr Manafort and his associates stopped responding to Mr Deripaska's queries about how the funds had been used.
As part of their investigation, US officials were expected to look into millions of dollars' worth of wire transfers to Mr Manafort.
In one case, reporters found that a Manafort-linked company received a one million dollar payment in October 2009 from a mysterious firm through the Bank of Cyprus.
The payment left the account the same day - split in two roughly equal disbursements to accounts with no obvious owner.
There is nothing inherently illicit about using multiple companies as Mr Manafort was doing, but it is unclear why he would have been involved with companies in Cyprus, known for its history of money-laundering before joining the European Union, with unclear sources of the money flowing into them and with such secrecy surrounding the firms' connections to Mr Manafort.
A US treasury department spokesman, Stephen Hudak, declined to answer questions about Mr Manafort's records.
He said: "We often get press inquiries concerning individuals and our policy is to never confirm, nor deny the existence, or non-existence, of any potential investigation."
Cypriot officials said further information would have to come to the agency through a formal request to the Cypriot ministry of justice and public order - under a mutual legal assistance treaty - although no request has been made, according sources.
Democrats on Capitol Hill who are part of two congressional investigations of Trump associates said the new disclosures about Mr Manafort's work for the Russian billionaire guarantee that he will be sought as a key witness in upcoming hearings.
Senator Martin Heinrich, who is a member of the Senate intelligence committee, said revelations about Mr Manafort's work were "serious and disturbing".
Democratic representative Jackie Speier of California, a member of the House intelligence committee, said reports about Mr Manafort's activities "undermines the groundless assertions that the administration has been making that there are no ties between President Trump and Russia".
She added: "This is not a drip, drip, drip. This is now dam-breaking, with water flushing out with all kinds of entanglements."
The White House said Mr Trump had not been aware of Mr Manafort's work on behalf of Mr Deripaska, a close ally of Mr Putin, with whom Mr Manafort eventually signed a 10 million dollar annual contract, beginning in 2006.
"To suggest that the president knew who his clients were from 10 years ago is a bit insane," White House press secretary Sean Spicer said.
"I don't know what he got paid to do. There's no suggestion he did anything improper."