Gavin Henson was with friends who had been supporting the Ospreys

The Ospreys star, 25, was returning from his club's victory over Harlequins in London on Sunday when passengers reported the group became disruptive.

Transport police said they questioned four men after the train arrived in Cardiff. They were not arrested.

The club say Henson will face an internal investigation.

A British Transport Police spokesman said: "At 21:25 GMT on Sunday 2nd December, a group of men were reported to be behaving rowdily on a train from London to Swansea. They were met by British Transport Police officers at Cardiff Central.

'Spirits were high'

"A man aged 25 from Wick, a man aged 26 and a man aged 33 from Bridgend and a man aged 25 from St Brides Major were spoken to. All four men are helping police with inquiries."

Henson had scored all the points in the Ospreys' 19-8 win in London to help the Swansea-based club reach the EDF Energy Cup semi-finals.

Earlier on Tuesday an Ospreys' spokesman said: "After playing a crucial part in what proved to be a particularly satisfying victory for the Ospreys on Sunday afternoon, Gavin made the return journey from London via train with friends who had attended the match in support of the Ospreys.

"Spirits were high amongst the group given the nature of the victory, and the group apologises for any inconvenience caused to fellow passengers."

But later Ospreys director of rugby Kevin Hopkins said: "This is something we are looking into and it will be dealt with internally."

The Welsh Rugby Union said: "It's not a matter we feel we are in a position to comment on at the moment."

Henson lives in the Vale of Glamorgan with his singer girlfriend Charlotte Church and their baby daughter Ruby Megan.