Paul Manafort and Michael Flynn are struggling to manage their legal bills stemming from special counsel Robert Mueller's Russia probe, according to a report Friday.

Manafort, President Trump's former campaign chairman, and Flynn, the president's first national security adviser who resigned under pressure, are both central targets of Mueller's investigation.

After news outlets this week reported the FBI raided Manafort's home last month, he announced that his is changing his legal representation on Thursday, bringing on a firm, Miller & Chevalier, that specializes in financial crimes and foreign bribery cases.

But the Daily Beast reported Manafort left his old legal representation, WilmerHale, because he was struggling to pay them.

"Paul Manafort's resolve is limitless, but his resources are not," a person close to Manafort told the Daily Beast.

Flynn, meanwhile, is expected to soon create a legal defense fund to keep from going bankrupt, the report said.

Manafort and Flynn are key figures in Mueller's investigation, which along with a number of congressional committees, is looking into Russia's interference in the 2016 election and possible collusion with the Trump campaign.

Both men are under scrutiny for contacts they had with Russian officials or pro-Russian interests.