Special counsel Robert Mueller’s office obtained new tax and bank fraud charges against Paul Manafort and Richard Gates on Thursday, adding pressure on the former Trump campaign manager and his longtime deputy, who have been fighting the case.

The new indictment, obtained from a federal grand jury in Virginia, alleges the pair engaged in an extensive scheme to defraud multiple lenders and obtain more than $20 million in loans between 2015 and January 2017, including through doctoring statements to show millions of dollars in income they didn’t in fact earn.

The special counsel’s office continues to pursue a wide-ranging probe into Russia’s meddling in the 2016 election. The new charges come two days after an attorney pleaded guilty to lying about his contact with Mr. Gates.

“Paul Manafort is innocent of the allegations set out in the newly filed indictments and he is confident that he will be acquitted of all charges,” said Jason Maloni, a spokesman for Mr. Manafort. “The new allegations against Mr. Manafort, once again, have nothing to do with Russia and 2016 election interference/collusion.”

Representatives for Mr. Gates couldn’t immediately be reached for comment. A new lawyer for Mr. Gates entered an appearance in court on Thursday while his old lawyers are withdrawing, a sign that he may be planning to change his legal strategy.