5.20pm: Railway lines have reopened.
5pm: A body has been recovered from the tracks near to Peascliffe Tunnel at Grantham.
A police officer on the scene confirmed that there are not thought to be any suspicious circumstances surrounding the death.
A spokesman for Network Rail said no comment could be made while British Transport Police officers are conducting an investigation.
The lines are expected to open shortly.
A person has been hit by a train on the railway line at Grantham this afternoon (Monday).
British Transport Police officers are currently on the scene at Peascliffe Tunnel, in Belton Lane near Great Gonerby.
Trains travelling on the East Coast Main Line have been stopped both ways with significant delays of up to two hours currently expected.
For travel information, visit www.nationalrail.co.uk