The Maroon 5 vocalist is married to Victoria's Secret model Behati Prinsloo [Courtesy]

The popular American rockstar Adam Levine has found himself in controversy after a TikTok model accused him of cheating on his wife with her.

The model took to the video-sharing app where she narrated her version of things to her followers, detailing a year-long affair behind Levine’s wife’s back.

The Maroon 5 vocalist is married to Victoria's Secret model Behati Prinsloo, with whom he shares two children - and the pair recently revealed that a third is on the way.

“I was having an affair with a man who is married to a Victoria’s Secret model. At the time I was young and naïve and quite frankly I feel exploited. I was not in the scene like I was now so I was very easily manipulated,” the woman, who goes by the name Sumner Stroh, said in the clip.

The now-viral video has been watched over 20 million times in 24 hours.

The model proceeded to show screenshots where she alleged to be chatting with the rockstar, his Instagram-verified name visible at the corner of the screen.

 The model took to the video-sharing app where she narrated her version of things to her followers [Courtesy]

“Adam and I were seeing each other for about a year, and after I stopped talking to him for a couple of months, this is how he came back into my life,” Stroh said, before claiming that Levine asked if he could name his new child after her.

Levine has since come out to deny having an affair, however noting that he may have “crossed the line.”

"I used poor judgment in speaking with anyone other than my wife in ANY kind of flirtatious manner. I did not have an affair; nevertheless, I crossed the line during a regrettable period of my life," he told TMZ in a statement.

He added, "In certain instances it became inappropriate. I have addressed that and taken proactive steps to remedy this with my family."

The rockstar further took to Instagram early Tuesday to express his regret for the incident.

“A lot is being said about me right now and I want to clear the air. I used poor judgement in speaking with anyone other than my wife in any kind of flirtatious manner. I did not have an affair,” he wrote on an Instagram story.

 The rockstar further took to Instagram early Tuesday to express his regret for the incident [Courtesy]

He added: “My wife and family are all I care about in this world. To be this naïve and stupid enough to risk the only thing that truly matters to me was the greatest mistake I could ever make.”

Levine and Behati Prinsloo wed in July 2014.