OJ Simpson responds to claim he's Khloe Kardashian's biological father

OJ Simpson has acknowledged for the first time the rumours he is Khloe Kardashian's biological father.

Reports have gone back years that Khloe was conceived after a one-night stand between the former football star and Khloe's mum Kris Jenner, despite Simpson being married to Nicole Brown Simpson and Jenner being married to Robert Kardashian at the time.

When asked by TMZ if he wanted to congratulate Khloe on her recent pregnancy news, Simpson replied "Well, for Bob [Robert Kardashian], God bless his soul, yeah. I don't know for me. I don't think for me I have nothing to do with it."

"I would be proud, but trust me, I had nothing to do with it."

OJ Simpson denied persistent rumours he fathered Khloe Kardashian. Photo / Getty Images

The two couples were close in the years before Brown Simpson's murder, and Kardashian went on to defend Simpson when he was on trial for her death in 1995. He was found not guilty.

In 2013, Simpson's ex-manager Norman Pardo told InTouch Weekly he believed OJ was Khloe's real dad.

"It's all going to come out sooner or later," Pardo said.

"They all [OJ, Nicole, Kris, Robert] took their vacations together. There was a lot of partying going on back then. Kris cheated on Robert — she was known for having a good time," he said.

Khloe has long denied she is Simpson's offspring — even after a National Enquirer report last year that Simpson had changed his will to include her.

She furiously hit back after being bombarded by trolls on social media about her "dad" being released from prison after Simpson was granted parole.

Robert Kardashian, right, defended OJ Simpson when he was charged with murdered his former wife Nicole Brown Simpson. Photo / AP

Khloe responded to the wave of abuse dominating her Instagram comments by branding the trolls "a**holes" and "haters".

Kris Jenner has also denied the allegations.

She slammed speculation about her daughter's parentage as "crap" in 2012 on Good Morning America.

"It just gets weirder and weirder: I have never heard such crap in my life. I mean, I was there! I gave birth, I know who the dad was."