It has emerged the Garda Ombudsman Commission is investigating last night's crash on the M50 in Dublin.
One man is in a critical condition while six others, including three children, are being treated for injuries.
Five vehicles were involved in the pile-up on the motorway, near the Ballinteer exit.
It is believed a car being pursued entered the southbound lane against the flow of traffic just before the collision.
Garda Síochána Ombudsman Commission (GSOC) spokesman Graham Doyle said: "The matter was referred to us by the Garda Commissioner last night…That's standard procedure in incidents such as this."