Brigitte Nielsen
Brigitte Nielsen attends the taping of a television show in Bottrop, Germany, May 9, 2015. Getty Images

Brigitte Nielsen, Sylvester Stallone's ex-wife, denied claims that the "Rocky" actor sexually assaulted a 16-year-old girl in Las Vegas in 1986. Nielsen told TMZ late Sunday the story is a lie as Stallone was with her the entire time in Las Vegas.

"During the summer of 1986 we were newlyweds. I was inseparable with Sylvester when 'Over the Top' was being shot in Las Vegas. The story claims that at approximately 8:30 in the evening during the shoot of the movie the person claims she was in our suite at the Hilton Hotel," Nielsen said, according to TMZ. "This incident did not occur. Most of the day, I would watch him film, then we'd have dinner and go to our room. No other person was in the room with him, but me."

Nielsen, a Danish actress, married Stallone on Dec. 15, 1985, at the Beverly Hills, California home of producer Irwin Winkler. Their marriage lasted just 19 months, with their divorce finalized July 1987. She is currently married to Mattia Dessi, who is the actress' fifth husband.

Nielsen, who hasn't spoken to Stallone in nearly 30 years, said: "I can say for certain that it is impossible for this incident to have occurred," adding, "It's unbelievable that Sylvester and his family have to suffer through this over something that never happened."

The Daily Mail reported last week a 16-year-old accused the actor of allegedly forcing her to have oral sex with him as his bodyguard Michael De Luca raped her. The teenager, according to the report, said she was “very uncomfortable” but felt like she had “no choice” but to engage. Stallone allegedly threatened her, claiming they would “have to beat her head in” if she told anyone.

The Daily Mail report said the teenage girl was introduced to Stallone by his "Over the Top" co-star, David Mendenhall.

Mendenhall told TMZ: "I was shocked when I read the Daily Mail article. It's completely false that I introduced a 16-year-old female stranger to Mr. Stallone near an elevator in the Hilton, or anywhere else for that matter," adding, "The only people I introduced to Mr. Stallone were my relatives who visited me on the set."

On Thursday, Stallone responded to sexual assault allegations leveled against him in a statement issued by his spokeswoman Michelle Bega: "This is a ridiculous, categorically false story. No one was ever aware of this story until it was published today, including Mr. Stallone. At no time was Mr. Stallone ever contacted by authorities or anyone else regarding this matter."

Neilsen, who is Stallone's second wife, began her career modeling for Greg Gorman and Helmut Newton and later acted in the 1985 films "Red Sonja" and "Rocky IV." Nielsen battled alcoholism for years and had also checked into a rehab in 2007. She has four children, but none of them are from Stallone.