VICTORIA'S transport safety watchdog is considering legal action against rail operator Metro and one of its drivers over a collision near Craigieburn last year in which a Melbourne suburban train rammed into a stationery freight train.

The driver of the suburban train failed to follow signalling rules, which required him to be travelling at 25 km/h - instead of about 60 km/h.

Investigations into the crash by both Public Transport Safety Victoria (PTSV) and the Department of Transport's chief investigator are complete, and may be released as soon as tomorrow.

Metro has already been forced to pay $1.9 million to repair the damage done to the suburban Comeng train that was involved in the crash.

PTSV director Alan Osborne told The Age he was in discussion with barristers about legal action against ''the parties'' involved in the incident.

He said his investigation had focused on ''whether Metro and the driver did the job they should have done in terms of the Rail Safety Act''.

Five of the suburban train's 15 passengers were hospitalised and rail services were stopped for at least two days after the collision in May last year. The outbound Pacific National freight train had stopped at a red light signal near Craigieburn station.

Metro sacked its driver concerned for failing to stop at a red signal, exceeding the 25 km/h speed limit, and for failing to co-operate with the investigation into the crash.

Mr Osborne said he was considering action against ''all parties'', an apparent reference to both the driver and Metro as the operator of the rail system.

''I am not saying I am targeting Metro in any one specific sense but I'm looking very seriously at 'were all the right things done'?''

The Craigieburn crash was one of a series of rail safety scares on the Melbourne network last year. In March last year, after a signalling failure, a Metro train collided with a freight train at Ringwood station. A report released by the chief investigator this week found poor communication among rail staff had contributed to the accident.

A report by Metro in 2009, before it took over from Connex, warned the former Brumby government that Melbourne's poor rail conditions ''have the potential to cause derailment of trains … with catastrophic consequences''.

Story provided by: theage.com.au