One of the NSW north coast police officers present when a young Aboriginal man was allegedly assaulted later joked to a friend "I got away with it," the Police Integrity Commission has heard.

The same officer then told another mate that he was planning to treat the commission's inquiry "with contempt", declaring "I'm gonna go f--- youse, I'll play your game".

The commission is investigating allegations that Corey Barker, 24, was assaulted at Ballina police station in northern NSW on January 14, 2011, after an altercation with police, and that officers then falsely accused the young man of assaulting them.

Under examination on Tuesday, Senior Constable Mark Woolvern was played a series of phone conversations he had with friends after the incident which were secretly recorded by the commission's investigators.