All power was cut to the rails at Dartford station after a person fell onto the track.
British Transport Police and the ambulance service are currently dealing with the situation.
A BTP spokesman said: "An elderly man had fallen onto the tracks. The ambulance service took the lead and we were called to assist them.
"It looks completley non-suspicious."
Southeastern has said that all trains had to diverted away from Dartford whilst the emergency services deal with the person.
It is not known if any serious injuries have occurred yet.
Southeastern said: "All power to the track was discharged for approximately 25 minutes, and no trains were able to run via Dartford during this time.
"All staff are now clear of the line at Dartford, and power has been restored to all lines.
"Some cancellations and short notice alterations will be necessary to help restore service to normal."
Trains running to Dartford may be cancelled, delayed or revised - with commuters being warned that disruption is expected until 5pm.
We will bring you more information on this story as we get it.
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