London Midland have warned commuters of potential rail delays because of a suspected trespasser.
The rail company tweeted this afternoon that train users should expected a 20 minute delay on all trains to and from Bletchley.
Some service alterations were also expected following reports of a trespasser on the line.
London Midland have since tweeted that the trespasser has been located, however those travelling to and from London should continue to expect delays.
The 6.12pm train to Tring (due 6.52pm) has been cancelled.