Former federal prosecutor Preet Bharara has signed on as counsel for Sen. Adam Schiff (D-CA) to fight the new criminal investigation the Trump administration has launched into him.

The investigation, led by Ed Martin, will examine whether Schiff committed mortgage fraud by holding primary residences in California and Maryland at the same time — a common practice for members of Congress that experts say, as long as all applicable state laws are followed, is not illegal. A spokesman for Schiff clarified he did not mislead any mortgage lender about his use of either property.

New York Attorney General Letitia James is reportedly being investigated as part of the same probe.

Bharara issued a scathing statement against the investigation, Politico's Kyle Cheney reported.

"The allegations against Senator Schiff are transparently false, stale, and long debunked," said Bharara. "Now Ed Martin, the most brazenly partisan and politically compromised person possible for the task, has been picked to investigate a political adversary. The bias here is glaring. Mr. Martin's nomination to be U.S. Attorney of the District of Columbia was derailed not only by his partisanship and unfitness, but also by the hold Senator Schiff appropriately placed on the nomination."

"Mr. Martin is a January 6-defending lawyer who has repeatedly pursued baseless and politically-motivated investigations to fulfill demands to investigate and prosecute perceived enemies. Any supposed investigation led by him would be the very definition of weaponization of the justice process."

Martin was previously appointed as Trump's acting U.S. Attorney for the District of Columbia, but after a string of high-profile and baseless legal threats against people and groups Trump was annoyed at, GOP senators made clear they would not provide the votes to confirm him. Trump moved Martin into the U.S. pardon attorney's office to keep him in the DOJ.