Police say the organisers of a protest march against alleged misconduct by officers during last weekend's Sydney Mardi Gras have shown "little willingness" to meet with officers.

Demonstrators are expected to march from Taylor Square in Darlinghurst to the Sydney Police Centre in Surry Hills about 6pm (AEDT) on Friday night, to demand an external investigation, apologies and compensation for alleged police brutality.

Politicians and community groups 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 about 11.30pm (AEDT) on Saturday.

It is understood Mr Jackson has been charged with assaulting police and an internal investigation has been launched.

Police have also launched two more internal investigations after complaints had been made into two separate incidents relating to alleged misconduct by police at the festival.

Police said the group which organised tonight's protest, Community Action Against Homophobia, have not sought formal approval to conduct a lawful protest but have indicated the proposed route and timing.

"We have approached protest organisers in the spirit of co-operation to ensure a safe and secure environment in which protest activities can take place," Surry Hills Local Area Commander Superintendent Tony Crandell said.

"At this stage there has been little willingness from organisers to meet with us."

He said police respect the democratic right to peaceful protest and are mindful that a number of participants are prominent members of the gay community with whom police have strong relationships.

Traffic disruptions are expected in and around Oxford, Pelican, Goulburn and Riley streets between 6pm and 8pm because of the protest and motorists are being urged to avoid the area.