Police are appealing for "specific witnesses" following a report of "outraging public decency" on a train, which travelled from Belfast to Londonderry.
Sergeant McCollam said:
“It was reported that at approximately 3.15pm on Sunday 10th September of this year, a man committed an act of outraging public decency on a train travelling from Belfast to the city (Derry/Londonderry).
“We are keen to specifically talk with a man and a woman, with a teenage girl, who may have been made aware of this incident by another witness after the train had stopped in Derry/Londonderry.
“The suspect was described as a man in his 50s with dark greying hair and clean shaven. He was wearing a dark suit and a white shirt.
“We would appeal to anyone who may have witnessed this, or has any information that may assist our enquiries, to contact police on 101, quoting reference number 746 of 12/09/23 or by making a report online via http://www.psni.police.uk/makeareport/.
“You can also contact Crimestoppers anonymously on 0800 555 111 or online at http://crimestoppers-uk.org/”