Mardi Gras video 'doesn't change things' - Sydney Morning Herald

AAP

New footage of an alleged police brutality victim lashing out at officers at Saturday night's Mardi Gras "doesn't change anything" about the need for a full investigation, independent Sydney MP Alex Greenwich says.

Thousands of demonstrators are expected to march from Taylor Square in Darlinghurst to the Sydney Police Centre in Surry Hills about 6pm (AEDT) on Friday.

Politicians and gay community groups have called for an inquiry after a video emerged that appeared to show a handcuffed 18-year-old, Jamie Jackson, being thrown to the ground by an officer at the festival.

A longer video of the incident shows Mr Jackson kicking and lashing out at an officer before he was restrained.

Mr Jackson has been charged with assaulting police, and an internal investigation has been launched into that incident and two others.

Another man, Bryn Hutchison, has been similarly charged over a separate incident.

Speaking a couple of hours before the march, Mr Greenwich said the planned protest was necessary, despite the new footage of Mr Jackson's clash with police.

"I don't think it changes anything. We know we need a full and thorough investigation. We need to know the whole picture," Mr Greenwich told reporters on Oxford street.

He said the rally demonstrated the "strength of the LGBTI community" and was not targeted at police.

"I don't think this is an anti-police rally," he said.

"I think this is a pro-action rally, and that's what will be occurring."

He said he understood a number of incidents were still being investigated from last Saturday's parade and encouraged "people to come forward and share their experiences".

He also said a forum would be held next Thursday at Surry Hills police station where officers and the community could "share their concerns".

Forty officers have been assigned to patrol the march down Oxford street and more than 2120 people have indicated on Facebook that they will attend the rally.

Motorists should expect rolling street closures along the march route, including Oxford and Flinders streets, police have advised.