OAKLAND (CBS SF) — An internal affairs investigation is underway focusing on several Oakland police officers who allegedly had sex with an underage girl.

Sources told KPIX 5 the internal affairs investigation centers around a young woman named Celeste Guap, who was underage at the time. She recently began revealing details of her relationships with officers on her Facebook page.

Guap is currently either 18 or 19 years old, according to sources, who also say investigators believe Guap had sex with potentially dozens of police officers beginning when she was 16.

On her Facebook page, Guap suggests she is involved in the sex scandal, but says she never snitched on anybody.

She said she had “harmless relationships” within the police department.

As recently as last month, Guap posted a picture of Oakland police officers dropping her off near her home.

“Took me back to Richmond in style,” she wrote.

In another post, she says the only officer she messed with while underage is sadly gone.

Oakland Police Officer Brendan O’Brien committed suicide last September about a year after his wife’s death was also ruled a suicide.

Investigators say O’Brien left a note that lead to an initial internal affairs investigation.

A subsequent investigation ordered by a federal judge led to many Oakland police officers admitting they had lied during the first internal affairs investigation about their relationships with Guap.

Sources say one officer also admitted to knowing she was underage when he had sex with her.

Oakland Police Department spokeswoman Johnna Watson said only that there is an investigation underway involving three officers, but wouldn’t give any specifics.

Watson admitted there were serious concerns in the department about the incident.

“We are entrusted by the community to protect, to serve them and to uphold the law. So we take the allegations very seriously,” said Watson.

Guap’s mother works with the police officers as a dispatcher with the Oakland Police Department.

In addition to the internal investigation, there is an ongoing criminal investigation happening in connection with the activities of the officers.