The Police Integrity Commission will investigate allegations police officers trolled NSW Greens MP Jenny Leong on social media.
It comes after it was revealed high-ranking police officers were allegedly posting racist and sexist comments on Ms Leong's Facebook page.
The PIC's Operation Colchester will investigate "whether there was any police misconduct in comments" made on a photo published on the site on March 18, a statement from the police body said on Thursday.
The photo depicts police officers with a drug detection dog on a train.
The alleged spate of cyber-bullying came a day after Ms Leong introduced a bill to the NSW Lower House to end the use of drug detection dogs in public places without a warrant.
Ms Leong welcomed the PIC's decision, saying her office would assist with the investigation.
"We will await the findings of the inquiry before further comment is made," she said in a statement.
The Greens member for Newtown said she would continue working to repeal the state's "ineffective" drug detection program.
"The outpouring of concern, care and commitment to seeing an end to racism and sexism in our community has been truly heartening in the face of such vile online abuse," she added.
Acting Deputy Commissioner Geoffrey McKechnie condemned the comments last week and announced NSW Police would investigate the matter.
NSW Police also sent out a message to all police officers reinforcing the organisation's social media policy.
