NHS Ayrshire and Arran said the interview panel had rejected all three candidates interviewed on Friday for the vacant post on the Isle of Cumbrae.
The Herald revealed the health board had been spending around £50,000 a month on locums since Cumbrae's three previous GPs quit in April 2013 following a long-running row over the opening of a pharmacy.
Islanders had hoped the latest recruitment drive, which attracted more applications than ever before, would finally resolve the crisis.
However, none of the three were considered suitable to take over Cumbrae Medical Practice in Millport and a "unanimous decision" was reached by the interview panel to reject all three applicants. It is understood that the health board will attempt to recruit a permanent GP again in around three months.
Jean Kerr, chair of the Cumbrae Elderly Forum and a member of the community's Public Reference Group, which was also involved in the interview process, said the result was "very disappointing".
However, Mrs Kerr said the PRG supported the decision. She said: "None of the candidates were 100% suitable, for various reasons. They were all very different but it was a mixture of problems with experience or availability. They each had excellent points, but no one had everything we were looking for. It's all getting a bit ridiculous now, but we're not going to appoint someone just for the sake of it. That's the last thing we want to do."
The practice was previously run for 27 years by Drs Jim and Elizabeth Bryson, but the couple took early retirement after the opening of a pharmacy in Millport forced them to close their in-house drug dispensary.
Income from the dispensary had helped fund a third GP, as well as house calls and out-of-hours care. The loss of the facility has been seen as a major stumbling block to hiring a new GP.
Local MSP Kenneth Gibson said the island was back to square one. He added: "For the forseeable future, Cumbrae will continue to be served by locums, an expensive and wholly unsatisfactory solution. The health board must pull out all the stops to secure an island based GP practice. Needless to say, the loss of GP dispensing precipitated this crisis and the board now has to reflect on this and put it right."
A spokeswoman for NHS Ayrshire and Arran said: "We will now reflect on the situation and engage further with the Public Reference Group before re-advertising the contract.
"NHS Ayrshire & Arran will continue to ensure that there is safe, effective locum GP cover on the island until a permanent appointment can be made."