Russell Brand has been accused of rape, sexual assaults and emotional abuse during a seven-year period at the height of his fame.
Four women, including one who was just 16 at the time, have alleged sexual assaults occurred between 2006 and 2013, when Brand was working for BBC Radio 2 and Channel 4, as well as starring in Hollywood films.
The comedian and actor also faces allegations of controlling, abusive and predatory behaviour, following a joint investigation by The Sunday Times, The Times and Channel 4 Dispatches.
Brand vehemently denies the allegations and in a video posted online, stated all of his relationships have been "consensual", before accusing the media of a "co-ordinated attack".
It comes after Channel 4 Dispatches aired a 90-minute film titled Russell Brand: In Plain Sight last night, which saw four unidentified women detail their allegations, and other women speak of their experiences working with Brand on TV sets.
It included Brand's former personal assistant Helen Berger, who called him a "narcissist" in an interview for the programme.
Meanwhile, Brand appeared as scheduled at the 2,000-capacity Troubadour Wembley Park Theatre in northwest London to perform a sold-out comedy gig yesterday evening.
His show, titled Bipolarisation, had been due to begin at 7pm, but was delayed by more than 45 minutes and lasted around an hour.
While not directly addressing the allegations, audience members said that Brand said he hoped they could "appreciate" there were things he could not talk about during the set.
In his video statement, posted online ahead of the publication of the claims, Brand said he was facing a "litany of extremely egregious and aggressive attacks".
The 48-year-old continued: "These allegations pertain to the time when I was working in the mainstream, when I was in the newspapers all the time, when I was in the movies and as I have written about extensively in my books, I was very, very promiscuous."
He continued: "Now during that time of promiscuity the relationships I had were absolutely, always consensual. I was always transparent about that then, almost too transparent, and I am being transparent about it now as well.
"To see that transparency metastasised into something criminal, that I absolutely deny, makes me question is there another agenda at play."
Britain's Commons Culture, Media and Sport Committee chair Caroline Dinenage said that MPs would be "closely monitoring" the response to the allegations against Brand.
During his career, Brand achieved prominence as host of Big Brother's spin-off show Big Mouth for three years until 2007.
In a statement, Channel 4 said: "Channel 4 is appalled to learn of these deeply troubling allegations, including behaviour alleged to have taken place on programmes made for Channel 4 between 2004 and 2007."
In the wake of the #MeToo movement, Brand previously said he had no regrets about his previous sexual behaviour, claiming to have had intimate relationships with hundreds of women in the past.
Brand was married to US pop star Katy Perry from 2010 to 2012 but is now married to Laura Gallacher, the sister of presenter Kirsty, and the pair have two children, with a third on the way.
His new live comedy show, Russell Brand Bipolarisation, has three dates left in September.
Reporting: Press Association
