Actor Adam Deacon has said he stands by the women who have accused Noel Clarke of sexual harassment, claiming his former co-star sabotaged his career.
Deacon claimed to have been Mr Clarke's "victim" for 15 years and said his mental health had suffered as a result.
Mr Clarke has "vehemently" denied any sexual or criminal wrongdoing after 20 women came forward to accuse him.
Deacon appeared with Mr Clarke in 2006's Kidulthood and its 2008 follow-up Adulthood, which Mr Clarke also directed.
The pair fell out in 2010 over a spoof film Deacon wanted to make called Anuvahood, which was made and released the following year.
In 2015 Deacon was found guilty of harassment without violence after sending Mr Clarke abusive messages on social media.
Last week Mr Clarke, 45, was suspended by Bafta after extensive allegations of sexual harassment were published in The Guardian.
Bafta also suspended the outstanding British contribution to cinema prize it had given the actor and film-maker on 10 April.
Following the claims, the Met Police confirmed they had received a third party report relating to allegations of sexual offences by a man.
The allegations also led to ITV pulling the final episode of its crime drama Viewpoint, in which Mr Clarke played the leading role.
Writing on Twitter, Deacon said he believed "every single word" Mr Clarke's accusers had said about their allegedly "harrowing" experiences.
The 38-year-old said he had spoken out about Mr Clarke's "sociopathic" behaviour on multiple occasions, only to have his claims dismissed.
"I only wish that everyone had taken more notice of my words," he continued, saying it might have stopped Mr Clarke's "horrific abuse of power".
He said the events of the past week had served as "a small vindication" and that he was "now looking towards a fresh start".
Mr Clarke is known for playing Mickey Smith in Doctor Who from 2005 to 2010 and for his work in Sky crime drama Bulletproof.
Sky said last week it had halted Mr Clarke's involvement in any of its future productions, including Bulletproof's planned fourth series.
Mr Clarke has said he is "deeply sorry" for some of his actions while continuing to deny any sexual misconduct or criminal wrongdoing.
He said he would be seeking professional help "to educate myself and change for the better".
Mr Clarke and Deacon are both previous winners of Bafta's rising star award, having received the honour in 2009 and 2012 respectively.
The BBC has approached Mr Clarke for comment.