A federal judge Friday accepted the guilty plea of a Honolulu police officer who has agreed to cooperate with authorities in an ongoing public corruption investigation that already has resulted in the indictment of former Police Chief Louis Kealoha and his wife, former Deputy Prosecutor Katherine Kealoha.

The plea deal that U.S. District Chief Judge J. Michael Seabright accepted means Daniel Sellers, who is on leave from his Honolulu Police Department job, faces up to a year in prison and a maximum $100,000 fine when he is sentenced April 29 for disclosing confidential material, a misdemeanor.

Sellers, 40, pleaded guilty in exchange for prosecutors dropping felony charges alleging that he unlawfully entered and searched the home of Katherine Kealoha’s uncle, lied about it to a grand jury and lied to the FBI.

The Kealohas, Sellers and three other former officers of an elite criminal intelligence unit were charged by federal authorities in 2017 with scheming to frame the uncle for stealing the Kealohas’ mailbox.

The initial investigation of that relatively minor federal crime has over the past several years transformed into a major public corruption investigation, leading to the indictments of all six. Until Friday all had pleaded not guilty.

The case captured headlines recently when Prosecutor Keith Kaneshiro received a letter from federal authorities saying he also was a target of the investigation. Two of his deputies, Chasid Sapolu and Janice Futa, received less serious letters, indicating they were subjects of interest.

As an HPD officer, Sellers, who has served 21 years with the department, was assigned to investigate the alleged mailbox theft.

He told Seabright that in 2013 he disclosed confidential information obtained from a federal database to Katherine Kealoha, not in her capacity as a deputy prosecutor, but as an alleged crime victim, even though he knew doing so violated federal and HPD regulations. Sellers and Kealoha had been friends since high school.

Sellers said he wanted to “own up to what I’ve done wrong” and take responsibility for his actions.

Federal prosecutor Michael Wheat, who is overseeing the case, told Seabright that Sellers already has begun cooperating with authorities.

That cooperation has triggered speculation about what Sellers knows and whether it goes beyond the mailbox case.

“I would imagine, without having any information, that Mr. Sellers has provided valuable information,” Loretta Sheehan, a former federal prosecutor and member of the Honolulu Police Commission, told reporters following Friday’s court hearing. Sheehan attended the afternoon hearing.

Sellers wasn’t the first police officer to admit wrongdoing in the federal case.

Now-retired officer Niall Silva pleaded guilty in December 2016 to conspiring with other HPD officers and Katherine Kealoha to frame her uncle for the mailbox theft.

At Friday’s hearing Seabright questioned Sellers at length about the type of information the police officer disclosed and how he obtained the information because the judge wasn’t sure the plea deal met the requirements of the law.

Sellers, who worked in conjunction with U.S. authorities when investigating cases that potentially could be pursued as federal prosecutions, must have obtained the confidential information in his capacity as a federal agent in order for the disclosure charge to apply.

Sellers told the court he received the information in the course of the mailbox investigation and shared it with Katherine Kealoha in June 2013. The data included such things as personal addresses, driver’s license details, Social Security numbers and whether Kealoha’s uncle, Gerard Puana, owned a vehicle similar to one seen in a surveillance video that was part of the mailbox case, according to Sellers.

Seabright eventually agreed that the plea deal met the legal threshold but told Wheat that the document submitted by his office lacked the information establishing such a nexus, which became evident only at Friday’s hearing, the judge said.

“It took us a very long time to get there,” Seabright warned.