Investigators on Friday seized the phones of Mayor Eric Adams’s chief adviser, Ingrid Lewis-Martin, searched her Brooklyn home and served her with a grand jury subpoena, her lawyer said.

“Ingrid Lewis-Martin has been served with a subpoena from the Southern District of New York and her phones were given to the New York County district attorney’s office,” the lawyer, Arthur L. Aidala, said in a statement. “She will cooperate fully with any and all investigations,” he said, adding that Ms. Lewis-Martin was “not the target of any case of which we are aware.”

Ms. Lewis-Martin, speaking Friday evening on Mr. Aidala’s radio show, denied any wrongdoing.

“I don’t know anything,” she said. “I’ve done nothing. And I don’t think that there is anything to know.”

Later, apparently referring to herself and the mayor, she said that no one is perfect, “but we are not thieves.”

Ms. Lewis-Martin was served with the grand jury subpoena and told about the search on Friday when she landed at Kennedy International Airport, having returned from a vacation in Japan, and was met by two sets of investigators, one state and one federal.

The actions appear to be tied to two different investigations, though information about the morning’s events and the nature of the state inquiry was preliminary. Several people with knowledge of the matter confirmed that the two sets of investigators approached Ms. Lewis-Martin after she passed through customs, served her with the subpoena and seized her phones.