Paul Manafort, U.S. President Donald Trump's former campaign chairman who was convicted of tax and bank fraud, may be transferred to Rikers Island jail in New York to face state criminal charges, a person familiar with the matter said.

Manafort, 70, is serving a combined sentence of 7½ years in prison from two separate federal criminal cases, the longest term of anyone stemming from special counsel Robert Mueller's investigation into Russian interference in the 2016 U.S. election and contacts between Moscow and Trump's campaign.

The veteran Republican political operative, who was paid millions of dollars for his work for pro-Russian politicians in Ukraine, had been expected to be transferred to New York state custody in June, another person familiar with the matter said.