A person has been hit by a train near Kettering.
East Midlands Trains says services have been disrupted in the area.
The emergency services are dealing with the incident near Kettering.
Trains between London St Pancras International and Leicester are expected to be delayed by up to 60 minutes, cancelled or revised.
There is no firm estimate yet of how long disruption will last but it is likely to continue until at least 4pm.
Replacement bus services are being arranged to run between Kettering and both Wellingborough and Leicester.
Travellers are being told they can use London Midland services from Euston to Nuneaton, services via Northampton, and also between Bedford and Bletchley.