(Reuters) - The Manhattan district attorney is pursuing criminal charges against Paul Manafort, President Donald Trump’s former campaign chairman, whether or not Trump pardons him for his federal convictions, a person familiar with the matter said on Friday.

FILE PHOTO: Former Trump campaign manager Paul Manafort arrives for arraignment on a third superseding indictment against him by Special Counsel Robert Mueller on charges of witness tampering, at U.S. District Court in Washington, June 15, 2018. REUTERS/Jonathan Ernst//File Photo/File Photo

The charges originate from unpaid state taxes and likely are also related to loans, according to the source, who spoke on condition of anonymity because charges have not been filed.

A spokesman for Manhattan District Attorney Cyrus Vance declined to comment, and as did a spokesman for Manafort.

Manafort, 69, was convicted in Alexandria, Virginia, federal court in August of bank and tax fraud and pleaded guilty in a parallel criminal case in Washington, both part of the U.S. special counsel’s investigation of possible collusion between Russia and Trump’s 2016 campaign. He is scheduled for sentencing next month and could be sent to prison for a decade or more.

However, Trump has fueled speculation that he might pardon Manafort by not ruling out the prospect and by showing sympathy with his plight. During Manafort’s trial in Virginia, Trump called him a “very good person” and labeled the tax and bank fraud case against him “very sad.”

Under an unusual arrangement, Manafort’s attorney also kept Trump informed about his meetings with U.S. special counsel Robert Mueller after he agreed to cooperate, as Reuters reported in October.

A U.S. president can only issue pardons for federal crimes, so Manafort could still face prison if he is found guilty of any state charges. However, New York has broad double jeopardy protections that usually prevent the state from prosecuting a person for crimes arising from the same criminal conduct the federal government has prosecuted before.

But taxes are fair game, said Marc Scholl, a former prosecutor in the Manhattan District Attorney’s office, noting that the double jeopardy protections do not apply to state taxes.

New York amended the law in 2011 after state tax charges against New York hotel owner Leona Helmsley were thrown out because they were based on the “same criminal transaction” as her convictions on federal tax evasion.

After that, New York law recognized “that a failure to pay what is owed to the state is different than a failure to pay what is owed to the federal government even if it’s based on the same income,” Scholl said.

Democratic lawmakers in New York also have introduced legislation to do away with other protections to prevent people from being tried twice for the same crime in cases of presidential pardon. But the measure has not yet been adopted by the legislature in Albany.

The New York Times reported earlier on Friday that a grand jury in Manhattan state court was hearing evidence against Manafort. Bloomberg also reported on possible charges on Friday.

Reuters reported last year that some of Manafort’s New York property loans were under investigation by Vance. The state prosecutor issued subpoenas to lenders, including Federal Savings Bank of Chicago, a small bank that provided millions in loans to Manafort. But state prosecutors held off on pursuing their investigation to not impede Mueller’s work.

Manafort is the only person charged by Mueller to go to trial. Over 30 other people and three companies have either been indicted or pleaded guilty in the investigation of suspected Russian interference in 2016 to help Trump get elected. Both Trump and Russia have denied any wrongdoing.