The future of the proposed £29million Lake Torrent circuit in Northern Ireland has been thrown into major doubt after the development company behind the project went into receivership.
It had secured a three-year contract to host a World Superbikes round starting from the 2019 season, and was targeting other high-profile events in the future, such as a British Touring Car Championship round.
But progress on the track, situated around 40 minutes from Belfast, has since ground to a halt, with delays leading to World Superbike organisers deciding to visit Donington Park instead.
It has been reported that a search for possible old mineshafts on the former quarry site had contributed to the setbacks.
Manna Developments - the company headed by the circuit's brainchild, David Henderson - went into receivership earlier this week, raising fresh doubts about the project's viability.
A statement issued on behalf of Manna said "one particular planning issue" has meant the company has been unable to fulfil all of the conditions that have been put in place by those funding the project.
The company said its "funding partner is aware of the status of the planning... but remains committed to making the funds available" after the "resolution of the final outstanding planning issue".
The statement continued: "The MP for the area is entirely aware of the planning condition, which has caused such delay, and has been working diligently to try and bring a resolution for the benefit of Manna Developments, Lake Torrent and the people of Northern Ireland, not least those in his constituency.
"With a contract already in place to host the World Superbike Championship, everyone needs to work together to seize this once-in-a-lifetime opportunity to really further enhance Northern Ireland's reputation on the global motorsport stage."
Ben Willshire, managing director of Driven International - the firm that designed the circuit's layout - told Autosport: "On our side we were waiting for an update from Manna Developments.
"We've prepared all the drawings for the FIA and FIM but weren't actively working on the project and were waiting on the next steps.
"We've done all we can to help and it's a shame because I think the project has got huge potential."
Autosport has been unable to contact Henderson for comment.
The last attempt to build a new circuit in the UK, the Circuit of Wales, also encountered funding difficulties, and last June the Welsh Government refused to offer the financial guarantee to build the prospective British MotoGP venue.