The chief of staff to former Honolulu Mayor Kirk Caldwell testified as a witness before a federal grand jury Thursday, a month after receiving a subpoena as part of an ongoing public corruption investigation by the U.S. Department of Justice.

Gary Kurokawa, former deputy director of the city Department of Budget and Fiscal Services and former administrator of the city’s Real Property Assessment Division, let Caldwell know about the testimony after it concluded Thursday, Caldwell campaign spokesperson Glenna Wong told the Honolulu Star-Advertiser.

Caldwell’s former managing director, Roy Amemiya, former Corporation Counsel Donna Leong and former Honolulu Police Commission Chair Max Sword are accused of conspiring to defraud the government by setting up a payment to former Honolulu Police Chief Louis Kealoha for $250,000 to voluntarily leave the Honolulu Police Department in January 2017.

Caldwell pulled out of the governor’s race the day before Kurokawa testified, saying in a statement Wednesday that “lack of funding” and “lack of momentum” were his reasons for dropping out.

“Gary Kurokawa did advise Kirk Caldwell that he had been subpoenaed over a month ago, and did let Kirk know again after he testified,” Wong said in a statement. “The investigations do not have anything to do with Kirk Caldwell withdrawing from the race.”

She also said Caldwell has not received a target or subject letter, or any correspondence or interview request, from the DOJ in connection with the investigation.

Caldwell has said he does not believe his former Cabinet members did anything wrong. In February, he issued a statement saying he had “great confidence in the integrity of Ms. Leong, Mr. Amemiya and Mr. Sword.”

“I am confident they did not commit a crime and they will be acquitted when they get their day in court. As I understand it, this somehow involves the process that was used for the Kealoha severance agreement. I am confident that Donna Leong used and would always use the process she believed was right and legal. These are people of impeccable integrity and honor. I cannot fathom the hurt they and their families must feel. I can only say that I am confident of their innocence and ask that everyone consider the facts and not rush to judgment,” Caldwell told the Star-Advertiser on Feb. 5.

Amemiya, Leong and Sword turned themselves in to the FBI on Jan. 12 and entered pleas of not guilty.

The trial for Amemiya, Sword and Leong is set for June 13.

On April 15, the trio’s attorneys filed motions asking that a judge decide their fate rather than a jury. A hearing on the motions is scheduled for Thursday before U.S. District Judge Leslie E. Kobayashi.

The right to a jury trial may be waived only if the waiver is in writing; the government consents; the court accepts the waiver; and the waiver is made voluntarily, knowingly, and intelligently, according to the Federal Rules of Criminal Procedure.

On March 25, Kobayashi denied a motion by defense attorneys to dismiss the charges.

Kelly Thornton, director of media relations for the U.S. Attorney’s Office of the Southern District of California, which is handling the prosecution, did not immediately respond to a Star- Advertiser request for comment. Kurokawa’s attorney, William A. Harrison, did not immediately reply to a Star-Advertiser request for comment.