The hourly service was stopped on Friday after police launched an investigation into the licences which were held by the North of England Ambulance Service, the company which ran the bus route.

Hospital chiefs have vowed to get the bus back on the road again as soon as possible, although it will be run by a different operator.

A spokesperson for the Scarborough and North East Yorkshire Healthcare NHS Trust said: “Due to unforeseen circumstances we had to suspend the shuttle bus service on Friday. We are in the process of re-establishing the service as soon as possible.

“We would like to take this opportunity to apologise to patients, visitors and staff for any inconvenience.”

A police spokesperson added: “North Yorkshire Police’s investigation into the licences held by the company who operate the service is still at a very early stage and it would be inappropriate to comment further at this time.”

Mick Pilling, who campaigns for improvements at Bridlington Hospital, described the service as a “lifeline” for people in both towns.

He added: “My understanding is that the hospital trust is trying to get another company to step in. The service is so important not only to patients but also to people visiting sick friends and relatives.

“Since it was set up the bus has nearly always been full and people have come to rely on it. They need to get this sorted out as soon as possible.”

John Palethorpe, chairman of Improve North Yorks NHS Services, added: “They are taking services out of Scarborough, Whitby and Bridlington hospitals. Now it is costing patients a fortune just to attend appointments – God help those on benefits.”

A spokesman for North of England Ambulance Service confirmed: “We will no longer be providing the shuttle bus service between Scarborough and Bridlington hospital.

“Whether or not the trust have arranged for a new service or not is a matter for them but we will not be resuming that service.

“This is due to specifics with regard to vehicle licensing and taxation categories.”