Sean and friend Willie Hansbro were taken into custody on Thursday by the New York State Park Police, relating to an incident during a recent concert in Lewiston, New York.
The two have been charged with forcible touching, second degree unlawful imprisonment and sexual abuse in the third degree
"Both men were charged with misdemeanors and they both vehemently deny the allegations," the rapper's lawyer told MTV News. "I am confident that, after further investigation, both men will be vindicated."
Big Sean has been vocal about his support of Chris Brown in the past, following the R&B singer's assault on ex-girlfriend Rihanna in 2009.
His debut album Finally Famous reached number 3 on the US Billboard 200 in June.
Watch the video for Big Sean's single 'My Last' featuring Chris Brown below: