An investigation has been launched after tag readers on the M50 were tampered with yesterday.

A 48 year old man cut a number of wires on the bridge at around 9.30pm - meaning that hundreds of drivers were able to pass through "toll free".

The M50 was closed for a time as Garda negotiators communicated with the man.

He was arrested and taken Blanchardstown Garda Station and is due to appear before court today.