Irish Rail is investigating an incident where a used syringe, which was at the side of a DART seat, became stuck in a boy's finger.
The incident took place last Saturday when the boy and his parents were on the way to take a trip on the Christmas steam train from Dublin's Pearse Street Station when the incident occured.
A spokesman for Irish Rail said they were investigating the incident and they believe the syringe was put there earlier that day.
"Obviously this was a very distressing incident for the young boy and his family, and we have been liaising with them since the incident," he said.
"It does appear as if it was down the side of the seat completely out of sight. There was also an immediate check after the incident happened to ensure that there was no other material hidden or visible which could cause harm to passengers, and thankfully there was not.
"DARTs are cleaned thoroughly and regularly, including sides of seats to ensure that such incidents are prevented, so it may have been that the syringe was placed there earlier in the day while the train was in service."