The FBI seized the phone of former President Donald Trump's election attorney John Eastman last week, as per a new court filing from the conservative lawyer.

Eastman revealed the search and seizure in federal court in a lawsuit filed in New Mexico on Monda aiming at having his phone returned.

The revelation exposes steps taken by the Justice Department in recent weeks as part of its ongoing criminal investigation into the Jan. 6 riots.

More than 775 people have been arrested in connection with the Capitol attack. Some 280 have been charged with obstructing an official proceeding.

The home of former US Department of Justice (DOJ) official Jeffrey Clark was raided last week by federal agents from the Justice Department's Office of Inspector General, which is coordinating with the larger FBI and US attorney investigation into January 6, 2021, a source familiar with the matter previously said as quoted by CNN. That search, which included the participation of the Justice Department's inspector general, took place on the same day as Eastman's.

The inspector general is authorized to conduct searches and seizures and investigates allegations of legal violations by Justice Department employees. Following an investigation, the inspector general may refer potential criminal cases to prosecutors.

Eastman's attorneys cited a reference in the warrant to the inspector general's office potentially analyzing the phone's contents, though it is unclear how involved the watchdog may be in his case.

It is worth noting that Eastman and Clark have not been charged with any crime.

About six federal investigators approached Eastman in New Mexico last Wednesday as he was leaving a restaurant after dinner with his wife and a friend, according to court documents.

He was patted down and "forced to provide [facial] biometric data to open" the phone, as per Eastman's court filing.

Agents gained access to Eastman's email accounts on his iPhone 12 Pro, according to the filings.

Eastman's communications are the most recent to be included in extensive Justice Department investigations into January 6, 2021 attack on the US Capitol.

The agents "forced" him to unlock his phone, Eastman stated.

In court, he is requesting that a federal judge ordered the Justice Department to return his property, destroy any records obtained, and halt investigators' access to the phone.

Read more: Trump's aide may face prosecution for refusing to testify for Capitol Riots