Questions were raised over the firm's operation of the scheme after pensioners said they were regularly given tickets for destinations beyond where they had requested.

This practice could enable bus companies to claim back more than they are entitled to from the Scottish Government concessionary scheme which gives operators money back from the taxpayer for every journey made by a pass-carrying passenger.

Kirkcaldy residents Carol and Dennis Nevey, both 63, claim they have been given incorrect tickets on numerous occasions over a period of months.

The couple travel from their home in Winifred Crescent to the town centre bus station around three times a week. They collected 13 bus tickets over a period of seven days recently, with only four showing the correct destination.

Mr Nevey said: "We have spoken to other people who use the scheme who have also been given wrong tickets.

"It seems to be happening all the time. Once I was even issued with a ticket showing Inverkeithing as the destination even though I was only travelling to Invertiel Farm."

Mrs Nevey added: "Pensioners rely on this scheme to get around and if it was withdrawn it would have a huge impact on so many people.

"It is a disgrace if bus companies are able to claim back more from the funding than they are entitled to."

Responding to concerns, Robert Andrew, regional director of Stagecoach Scotland, said: "In order to fully investigate this issue, we would require a copy of the tickets in question.

"From the information we have, it would appear that driver error has resulted in tickets being issued to differing locations."

Mr Andrew explained that only fare stages were listed as destinations on tickets meaning there would also be legitimate instances where a destination further along the line would be shown which cost the same fare.

He urged passengers to make drivers aware of mistakes so that incorrect tickets can be cancelled and reissued.

He added: "The public can be assured that the reimbursement Stagecoach receives under the scheme is only that to which it is entitled and bus operator claims are independently checked by Transport Scotland."

Transport Scotland confirmed every concessionary travel claim is subject to a system of checks and analysis by its validation team.