UPDATE: Police officer and two others charged after alleged attempted Sydney robbery

Charges have been laid against three men, including a police officer, after they allegedly tried to steal from a woman carrying hundreds of thousands of dollars in Sydney's south-west.

The trio, all 29, were charged with robbery in company and three counts of stealing.

The officer, a male senior constable attached to the South West Metropolitan Region, is suspended without pay.

The alleged would-be robbers were wearing hi-viz clothing and wigs when they were pinned to the ground by police in Cabramatta.

Police believe their target was a woman walking out of a cash transfer store.

"I heard a commotion across the road on the footpath there, a woman was screaming and I saw a struggle," a witness said.

A man and a woman received minor injuries and were treated at the scene.

The trio were all refused bail and will appear before Liverpool Local Court tomorrow.