Michael D. Cohen, the onetime fixer for former President Donald J. Trump, said in court papers unsealed on Friday that he had mistakenly given his lawyer bogus legal citations generated by the artificial intelligence program Google Bard.

The fictitious citations were used by Mr. Cohen’s lawyer in a motion submitted to a federal judge, Jesse M. Furman. Mr. Cohen, who pleaded guilty in 2018 to campaign finance violations and served time in prison, had asked the judge for an early end to the court’s supervision of his case now that he is out of prison and has complied with the conditions of his release.

In a sworn declaration made public on Friday, Mr. Cohen explained that he had not kept up with “emerging trends (and related risks) in legal technology and did not realize that Google Bard was a generative text service that, like ChatGPT, could show citations and descriptions that looked real but actually were not.”

He also said he did not realize that the lawyer filing the motion on his behalf, David M. Schwartz, “would drop the cases into his submission wholesale without even confirming that they existed.”