Real Radio Scotland has been criticised by the broadcasting regulator, Ofcom, for giving a coach company just 20 minutes to respond to claims about its safety record.
The station was acting on a tip-off from a whistleblower working for Parks, owners of the coach involved in a fatal collision on the M4 last January in which two passengers died.
The source incorrectly claimed that Parks had decided not to withdraw its other coaches for safety checks.
Real Radio tried to contact the company at 10.40am, was told no one was available to comment, and broadcast the claims at 11am. The station made follow-up calls at noon and 2pm, to no avail, and repeated the story three times during the afternoon.
Ofcom has ruled that Real Radio was wrong to broadcast the story at 11am, as 20 minutes was not long enough to give the company time to respond to the serious allegations.
But the regulator said the station was justified in reporting the claims at midday, as there was a strong public interest defence for the story and the station had made reasonable attempts to contact the firm and verify the story.