Trains running north out of Potters Bar were delayed for a time on Tuesday afternoon after reports of a defect on the northbound line.

Some train services run by West Anglia Great Northern (WAGN) were delayed while investigations took place.

The checks were made less than three weeks after a suspected rail defect caused a major crash at the station in which seven people died.

More than 70 people were injured in the derailment on 10 May.

Faulty points

Trains began running again through the station on Monday 20 May.

The Health and Safety Executive has released an interim report confirming that missing rail nuts in a set of points probably caused the derailment.

The firm in charge of the line said photographs backed up its claim that sabotage had caused the crash.

But police investigating the derailment say they have so far found no evidence of vandalism or sabotage.

Rail experts have also dismissed the possibility of foul play.