OAKLAND (CBS SF) — The latest cop added to the growing list of Oakland police officers placed on administrative leave is accused of having his girlfriend help him write up his police reports, according to sources

Sources tell KPIX 5 that homicide investigator Sergeant Michael Gantt — who is married –had his girlfriend typing homicide reports for him, even though those reports are supposed to be confidential.

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KPIX 5 first reported the new investigation involving Gantt on Thursday.

Oakland Mayor Libby Schaaf acknowledged the officer being placed on leave in a statement released Thursday night, though she did not reveal the reason.

“We are still not at liberty to discuss details of any ongoing investigation without risking compromise of the investigation and potentially jeopardizing our efforts to hold wrongdoers accountable,” Schaaf said in a statement.

Gantt, who investigated hundreds of murder cases, is now under criminal misconduct investigation himself.

“It calls into question any case he’s ever investigated,” said Alameda County Public Defender Brendon Woods. “It calls into questions his credibility and his fitness as an officer.”

Defense attorney Annie Beles was also shocked at the latest accusation of police misconduct.

“Holy moly. I cannot believe the Oakland police would allow this type of stuff to happen,” said Beles.

Sources say Gantt’s girlfriend even posted a photo of a case file on her Instagram account. When KPIX 5 checked her page, it was revealed she had since deleted her account.

Sources say the photo showed the name of Mario Floyd, who’s facing trial in the high-profile killing of Judy Salamon.

KPIX 5 shot footage of Gantt at a 2014 press conference talking about the arrest.

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“Most Oakland police documents have at the top, ‘For law enforcement only, no public distribution allowed.’ So I’m shocked,” said Beles, who served as Floyd’s defense attorney.

Legal experts say it’s against the law for homicide detectives to share confidential investigative reports because that can taint witness testimony.

Defense attorneys could ask judges to throw out previous convictions and bring a halt to current cases.

“His credibility is an issue in every case he’s ever touched,” said Woods.

Sgt. Gantt is a 27-year-veteran and has investigated hundreds of cases.

In 2004, internal affairs investigated Gantt for interfering with a rape case. The department fired him, but he took the case to arbitration and won his job back.

The district attorney is not commenting on the case.

The Alameda County Public Defender Woods will now review all cases he investigated.

Some Oakland city leaders say this scandal has an even bigger impact on the city than the unrelated sexual misconduct case.

This all comes in a week when Schaaf has swapped out three different police chiefs. The latest temporary chief, Assistant Chief Paul Figueroa, was dismissed from the position late Friday.

District Attorney Nancy O’Malley said Wednesday that an inspector with her office has also been placed on administrative leave pending the results of an investigation into allegations that the inspector may have been connected to the sex scandal currently rocking the Oakland police.

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