CNN  — 

FBI seized the phone of former President Donald Trump’s election attorney John Eastman last week, according to a new court filing from the conservative lawyer.

Eastman disclosed the search and seizure in federal court in a lawsuit that he filed in New Mexico on Monday, calling it improper.

The revelation highlights the aggressive steps the Justice Department has taken in recent weeks as part of its ongoing criminal probe.

Federal agents from the Justice Department’s Office of Inspector General, which is coordinating with the wider FBI and US attorney investigation into January 6, 2021, last week raided the home of former DOJ official Jeffrey Clark, a source familiar previously told CNN. That search – during which the Justice Department inspector general’s participation had not been previously reported – came the same day as Eastman’s.

The inspector general investigates accusations of legal violations by Justice Department employees and has the ability to conduct searches and seizures. After investigating, the inspector general can refer possible criminal matters to prosecutors.

Eastman’s lawyers cited a reference in the warrant to the inspector general’s office potentially analyzing the phone’s contents, though it remains unclear to what extent the watchdog may be involved in his case.

Neither Eastman nor Clark have been charged with any crime.

Attorneys for Clark haven’t responded to requests for comment. A spokesperson for the DOJ inspector general’s office declined to comment on Monday.

Last Wednesday, about six federal investigators approached Eastman in New Mexico when he was exiting a restaurant after dinner with his wife and a friend, according to the court filings. He was patted down, and “forced to provide [facial] biometric data to open” the phone, Eastman’s court filing said.

Agents were able to get access to Eastman’s email accounts on his iPhone 12 Pro, the filings said.

Eastman is the latest person whose communications have become part of extensive Justice Department investigations related to the January 6, 2021, attack on the US Capitol.

Eastman contends the agents “forced” him to unlock his phone.

In court, he is asking a federal judge to force the Justice Department to return his property, destroy records they’ve obtained and put on hold investigators’ access to the phone.

This story has been updated with additional details.