London's Metropolitan Police said on Monday it had received multiple sex offence allegations following a week of news reports about British actor and comedian Russell Brand.

The 48-year-old has been the subject of rape and assault accusations, following a joint investigation by The Times, The Sunday Times and Channel 4 television which went public on September 16.

The outlets reported on claims against him by four women of rape, sexual assaults and emotional abuse, said to have taken place between 2006 and 2013.

Another woman also came forward days later to accuse him of exposing himself to her in 2008.

Police in London said early last week that they had received a report of alleged sexual assault following the revelations.

In an update Monday, the Met said that it has since received a "number of allegations of sexual offences in London" as well as elsewhere in the UK.

The force added in a short statement that all the allegations were non-recent and there have been no arrests.

"We continue to encourage anyone who believes they may have been a victim of a sexual offence, no matter how long ago it was, to contact us," Detective Superintendent Andy Furphy said.

"We understand it can feel like a difficult step to take and I want to reassure that we have a team of specialist officers available to advise and support."

Brand has denied the allegations, saying his relationships have always been "consensual", even during a period when he admitted being "very, very promiscuous".

During his regular online video platform show Brand said Monday he would talk about the "collusion between big tech and government and an apparent concerted effort by legacy media... to silence independent media voices".

"Obviously, it's difficult for me to be entirely objective given the events of the last week, but that's what we must try to do," he added, without directly addressing the new police update.