Federal investigators executed a search warrant today on former New York City mayor Rudy Giuliani, seizing electronic devices.

The raid on Giuliani comes as federal authorities were investigating whether he violated the law by lobbying the Trump administration on behalf of Ukrainian officials in 2019. Giuliani has served as former President Donald Trump’s personal attorney on a number of high-profile matters.

According to Giuliani’s attorney Robert Costello, seven FBI agents arrived at the apartment at 6 a.m. this morning and remained for roughly two hours. The agents seized several electronic devices including laptops and cell phones.

The warrant was based on suspicion that Giuliani violated the Foreign Agents Registration Act (FARA) in lobbying on behalf of Ukraine. FARA requires individuals to notify the State Department if they are acting as a foreign agent.

The FBI said they have no futher comment on this matter.

Giuliani was instrumental in Trump’s push to have Ukraine investigate then-candidate Joe Biden and his son Hunter regarding energy company Burisma Holdings, for which Hunter Biden served on the board.

Giuliani associates Lev Parnas and Igor Fruman have already been charged with crimes including campaign finance violations for allegedly funneling foreign money to various U.S. campaigns in order to gain influence over candidates.