Brand, 49, has denied the alleged abuses, which are said to have taken place between 2006 and 2013.
Peter Johnston, BBC director of editorial complaints and reviews, investigated eight complaints about Brand, only one of which was made formally to the BBC.
The review looked at a range of claims against Brand including that he urinated into cups or bottles while in the studio, threw objects, had sex on BBC premises and exposed himself in front of staff and guests.
“I have apologised on behalf of the BBC to those most directly affected,” Johnston said in his report.
“The culture of the time undoubtedly influenced what was acceptable/tolerated, but I have found that a number of individuals had concerns about Russell Brand’s behaviour which they felt unable to raise then.
“Many interviewees believed, rightly or wrongly, that Russell Brand would always get his way and therefore they stayed silent,” he added.
The review added that it acknowledged that Brand “categorically denies all public allegations made against him”.
In November 2024, London police said they had passed a file of evidence to state prosecutors to decide whether to bring charges.
According to the BBC a variety of “mechanisms and routes” are now in place for staff to raise any concerns they may have.
- Agence France-Presse