A TRAIN that caused chaos for commuters after it derailed in Eastleigh came off the tracks due to a "infrastructure fault".

The main railway line reopened through Eastleigh on Monday following the derailment of a freight train at the station and six days of emergency repair works.

It has now been revealed by Network Rail that the cause of the incident was infrastructure fault, when a small number of fastenings gave way.

This led to track spread - meaning that the two rails were no longer the correct distance apart.

However, Network Rail have warned that passengers using Eastleigh Station should always check before travelling as not all trains can call at the railway station.

John Halsall, Network Rail Southern Region Managing Director said: “The railway through Eastleigh has been reopened. The derailment caused a phenomenal amount of damage to the rail infrastructure; we are working as quickly as we can to restore the full service and apologise to those whose journeys are still affected. A new set of points is being constructed from scratch as the old set were damaged beyond repair, this will take time and will be completed in the coming weeks.

“We now understand the cause of the derailment.

"A small number of fastenings holding the track to the rail gave way causing track spread and the two rails were pushed apart.

"Passenger safety is our top priority; we have conducted detailed inspections of all other locations across the route where similar fastenings are found and no additional areas of concern have been identified through this work.”

Since the incident, Network Rail has carried out "enhanced precautionary" inspections of all similar fastenings across the Wessex route, with no additional areas of concern identified through this work.

Hydraulic jacks and cranes were used to lift the wagons back on to the track before they were removed from site.

The derailed train caused extensive damage to several sets of points, which allow trains to cross from one track to another.

These had to be removed completely and a new set will be built off site to a bespoke design, this is expected to be delivered over coming weeks.

More than 160 metres of temporary track has been laid to allow the reopening of the railway, however, without the critical points in place, not all trains can call at Eastleigh station.

The official Rail Industry Accident Board (RAIB) investigation is ongoing.