(CNN) Michael Cohen, President Donald Trump's personal attorney, has been "under criminal investigation" for months in New York because of his business dealings, the Justice Department said Friday.

The revelation comes amid a courtroom drama that unfolded Friday, as Cohen's attorneys and Trump's attorneys began a fight hours before with the US Attorney's Office in Manhattan over a massive raid of Cohen's records.

Cohen's attorneys have filed a temporary restraining order in the matter, asking the court to stop federal prosecutors from using some of the records they seized. Cohen did not appear in court Friday morning and has not been charged with a crime.

In response to Cohen's motion to prevent prosecutors from using evidence collected in Monday's raids of his home and office, the US attorney in New York asserted the raids were authorized by a federal judge to seek evidence of conduct "for which Cohen is under criminal investigation."

A court filing did not detail what Cohen is under investigation for.

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