Sean “Diddy” Combs is reportedly being investigated amid ex-girlfriend Cassie’s sexual assault lawsuit against him.

According to TMZ, the Bad Boys Records founder, 54, is the “subject of a secret NYPD investigation.”

Law sources told the outlet recently that there is a case file open with the name “Sean Combs,” however the document is “locked.”

“The NYPD takes sexual assault and rape cases extremely seriously, and urges anyone who has been a victim to file a police report so we can perform a comprehensive investigation, and offer support and services to survivors,” the insider said.

No police reports involving Cassie and Combs appear to be filed in the other cities that the “Me & U” singer, 37, mentions in her suit, including Miami, Beverly Hills and Los Angeles, TMZ reported.

However, a report from 2016 resurfaced, when Beverly Hills cops were called to a home and Combs and Cassie were having a dispute.

While a domestic incident report was written down, no legal litigation followed.

On Thursday, Cassie, whose real name is Casandra Ventura, accused the “Get Him to the Greek” actor of raping and physically abusing her for over a decade.

In court docs, she also claimed that he trafficked and harshly beat her throughout their relationship.

“After years in silence and darkness, I am finally ready to tell my story, and to speak up on behalf of myself and for the benefit of other women who face violence and abuse in their relationships,” the “Step Up 2: the Streets” star said in a statement through her lawyers at Wigdor LLP.

Additionally, she alleged that Combs gave her drugs and alcohol frequently and forced her to have sex with male prostitutes.

Ventura also alleged that the Sean John CEO blew up rapper Kid Cudi’s car when he found out that he wanted to date the singer in 2012.

“Over the years that Mr. Combs abused Ms. Ventura physically and sexually, she again and again tried to escape his tight hold over her life,” the lawsuit read.

The file went on: “Every time she hid, Mr. Combs’s vast network of corporations and affiliated entities found her, and those who worked for Mr. Combs’s companies implored her to return to him.”

The physical acts were reportedly witnessed by his staff, but no one “dared to speak up against their frightening and ferocious boss.”

“Many went as far as to explicitly state that her failure to return to Mr. Combs would hinder her success in the entertainment industry.”

Combs’ lawyer, Ben Brafman, told Page Six that his client “vehemently denies these offensive and outrageous allegations.”

The rapper alleged via Brafman that Ventura had been demanding $30 million from him for the last six months “under the threat of writing a damaging book about their relationship, which was unequivocally rejected as blatant blackmail.”

Ventura and Combs’ on-and-off-again relationship reportedly began in 2005 when she was 19 and Combs was 37.