Police used capsicum spray to subdue a man after an incident at Wollongong train station on Sunday.
Police Transport Command officers were arresting a teenager at the station about 4.30pm, when a man and woman tried to interfere with the arrest and began swearing, police said.
The man and woman were not related to the teenager.
Officers used oleoresin capsicum spray in the arrest of the 31-year-old man before he was taken to Wollongong Police Station and charged with hinder police, resist arrest and offensive language.
He will face Wollongong Local Court on December 5,