Warwickshire Hunt says reports that a hound had died after being struck by a train on the line between Fenny Compton and Bishop's Itchington during a New Year's Day hunt were incorrect.
All hounds were returned to the hunt kennels safely, a spokesman said.
British Transport Police confirmed that they attended an obstruction and trespass of hounds on the railway line and that they are continuing investigations.
Hounds followed a scent onto the railway line during the New Year's Day hunt.
Amy Lees of British Transport Police (BTP) said: "Shortly before 1pm on Wednesday January 1 British Transport Police were called to the line between Leamington Spa and Banbury station following a report of a group of trespassers and a dog struck by a train.
"BTP officers attended the scene and are currently investigating the circumstances surrounding the incident."
A spokesman for the hunt said: "Following an incident on January 1, 2020 in which British Transport Police were called, we can confirm that all hounds have returned safely to kennels.
"Any reports that a hound was killed is untrue. The Warwickshire Hunt will cooperate with any further investigation and apologises for any inconvenience caused during this incident.”
A report to the Banbury Guardian from the West Midlands Hunt Saboteurs (WMHS) said trains were stopped and delayed and transport police called to the mainline railway.
A spokesman for the WMHS said the group was not near to the hunt when the incident occurred.
"We were the other side of the hill in at Watergall. We are in contact with several eye witnesses who saw what happened. We are unsure at this time if any hounds were injured or killed," he said.
"This is the fourth time in a month that the Warwickshire Hunt hounds have rampaged out of control and caused chaos."
The hunt has apologised for incidents in which hounds have gone 'off-trail' through a field of rheas in Avon Dassett early in December, a graveyard in Idlicote just before Christmas and through gardens in Horley in mid December.
WMHS said trespassing on a live railway line is the only form of trespass that is a criminal offence.
"The Warwickshire Hunt have tried to pass the blame on to saboteurs for previous incidents of hound chaos, but they were nowhere near the hounds when this incident happened. They will have to come up with a different excuse."
On previous occasions the hunt has maintained that interference by saboteurs has confused hounds and led them away from a trail hunt that does not contravene the 2004 Hunting Act, which banned hunting wild mammals with dogs.