Police are appealing for information to identify a man after he allegedly committed two acts of indecency on trains in Macarthur earlier this year.
A man committed an act of indecency while travelling between Wolli Creek and Glenfield stations about 9.15pm on March 26.
The man boarded a second train that night and allegedly committed another act of indecency before departing at Leppington Railway Station.
Officers from the Police Transport Command received reports and launched an investigation into the incidents.
Police have now released images of a man they believe may be able to assist them with their inquiries.
The man is described as being of medium build and aged in his 20s, with a goatee beard.
He was last seen wearing a grey t-shirt, black tracksuit pants with a hooded jumper tied around his waist, and a dark coloured cap on backwards.
Anyone with information or who can identify the man is urged to contact police via Crime Stoppers.on 1800 333 000.