A LARGE quantity of prescription tranquilisers have been left by a passenger on board an Arriva Wales train this morning (Monday).

Police in Milford Haven were alerted earlier today by a passenger who realised they had left the drugs - including diazepam and other tranquilisers - on the train.

The person had been travelling between Port Talbot and Milford Haven.

Sergeant Terri Harrison said the drugs can be dangerous if consumed, and are intended only to be taken by prescription.

The medication was stored in a blue Nivea washbag.

Anyone who find the bag should hand it in to train staff.