Trains disrupted between Cardiff and Newport
Rail passengers have been facing delays between Cardiff Central and Newport after a man's body was found on the line.
First Great Western (FGW), Arriva Trains Wales and CrossCountry services have all been affected.
The body was spotted by a train driver at Marshfield at 06:45 BST. His death is being treated as "unexplained".
Trains were suspended but back running by 09:30 BST, with delays of up to 45 minutes.
Replacement buses were brought in between Cardiff and Newport.
A FGW spokesperson said: "Services between Cardiff and Newport have been suspended due to an incident on the line at Marshfield.
"Police are in attendance but we expect there to be ongoing cancellations and delays for the remainder of the morning.
"Extra buses are in place and we advise people to call National Rail Enquiries or check online before travelling."
Arriva Trains Wales currently does not have an estimate as to when a normal service will resume.
Services are now able to run on their normal routes with some residual delays possible. Buses are still running to supplement the train service.
CrossCountry Trains said it expects delays to last until around 10:15 BST.
There are also delays between Cardiff and Ebbw Vale Parkway, which goes through Newport, and some ongoing services to Swansea and Maesteg.
The 07:30 BST service from Cardiff Central to Portsmouth was started from Bristol Temple Meads, while the 08:45 from Cardiff to Nottingham was cancelled.
One passenger tweeted that First Great Western were handing out free coffees and teas on the train while it was stood still between Cardiff and Newport.
A British Transport Police (BTP) spokesman said officers were called to the line at Marshfield Road, Cardiff at 06:45 BST on Tuesday after a report of a body on the line.
A man's body was discovered by police, Network Rail staff and paramedics.
"The driver of a train passing the location spotted the body on the line," said a BTP spokesman.
"The body was not hit by this train. The incident is currently being treated as unexplained and enquiries are ongoing to establish the man's identity and the full circumstances surrounding the incident."
The incident has caused delays for passengers using the mainline in South Wales. For travel information please contact National Rail Enquiries on 08457 48 49 50.