Victoria's train services suffered chaotic delays on Tuesday morning as power was cut on Metro's transport system at about 0500 AEST when a train got entangled by overhead broken wires between South Cross station and North Melbourne station.

Metro chief executive Andrew Lezala said that power was restored by 0745 AEST as the trapped train was freed but he said delays would still be seen the whole morning as he issued apologies to commuters for the inconveniences caused by the problem.

Mr Lezala assured the riding public that Metro was doing its best to restore normal operations by noon time as he revealed that ageing rail infrastructure had been the cause of the power outage specifying that "it was a fatigue failure in the wire itself, a crack triggered by wear, the movement of the pantograph and the tension in the wire itself."

He also admitted that the delays had spillover effects on regional train services and V/Line passengers could expect significant delays in their approximated travel time.

Metro users had expressed frustrations that the system's staff failed to quickly react on the problems created by the power failure and scored the lack of proper information during the height of the confusion, which further complicated the already tense situation.

Passenger John Wilson complained of inaccurate information on what train to catch instead in order to avoid being late as he ended up an hour late just because the train system's authorities were not able to properly coordinate their operation during the chaos, which should attract more concerns on Metro's handling of the rail system.

On his part, Premier John Brumby gave assurance that he would require Metro to file a full report on the latest incident as he stressed that the system's average start has been improving, adding that "Metro is here for the long haul and they're continually improving their performance. It is also very clear to them that we expect the highest standards of performance."