South West Trains said that all services had been brought to a halt by the incident.
The company say they were briefly stopped and were now normal.
Thousands of passengers would have been on trains on that section of line at the height of the rush hour.
More top news
A restaurant boss has been told to pay more than £4,750 after admitting a catalogue of hygiene offences.
Serial killer, Peter Tobin, has been taken to hospital after being found slumped in his cell.
Monday afternoon's weather for the west of the region