The handling of the federal investigation into Democratic Sen. Adam Schiff of California is being reviewed by Justice Department investigators, three sources familiar with the matter told CBS News.

A Republican congressional candidate who lives in California, Christine Bish, submitted a tip to the Federal Housing Finance Agency, alleging fraud in Schiff’s mortgage documentation. She told CBS News that she was questioned by federal officials Thursday and was asked about Bill Pulte. He’s the head of the Federal Housing Finance Agency and was appointed to the position by President Trump. Pulte referred Schiff to the Justice Department in May for investigation over alleged mortgage fraud. 

Schiff has denied any wrongdoing, and on Thursday declined to comment when asked about Pulte.

Bish said the officials “weren’t asking me about Schiff — they were asking me about other people who were investigating Schiff.”

In addition to Schiff, Pulte recently referred California Democratic Rep. Eric Swalwell to the Justice Department for investigation over alleged tax and mortgage fraud and has leveled similar accusations against several other officials, including New York Attorney General Letitia James, a Democrat, and Federal Reserve Governor Lisa Cook. 

Bish said federal officials also wanted to know if she had ever met Pulte or Ed Martin, who is the Justice Department’s pardon attorney and also the director of its Weaponization Working Group.

“That’s what they’re looking for, is that, and any communication that I’ve had with them,” Bish said. She told CBS News she has not communicated with either of them.

Bish was at the Greenbelt, Maryland, federal courthouse Thursday and spoke with reporters. She said was not under oath when she spoke with federal officials. 

Two other sources familiar with the matter said there is a review underway into how Pulte and Martin have handled the investigation of Schiff.

A copy of a subpoena shared by Bish said she has been asked to provide “documentation and communications” she referenced in her interviews with federal agents about Schiff. Specifically, the subpoena said Bish was to provide information about “any person or persons claiming to be William Pulte,” any person or persons claiming to be working at the direction of Pulte” and “anyone claiming to be working for or at the direction” of the Justice Department and Ed Martin, who is working on the investigation into Schiff.

The Justice Department declined to comment.