A policeman has allegedly been kicked in the face by a man who didn't have a train ticket at a Sydney station.

A policeman has allegedly been kicked in the face by a man who didn't have a train ticket at a Sydney station.

Officers tried to arrest the man at Liverpool Railway Station on Thursday night, before he allegedly tripped a male officer to the ground and kicked him.

Officers tried to arrest the man at Liverpool Railway Station on Thursday night, before he allegedly tripped a male officer to the ground and kicked him.