The British Racing Drivers' Club has played down claims by a consortium involving Nigel Mansell that it has saved the British Grand Prix.
Mansell is on the board of directors at Brand Synergy Ltd
The BRDC, owners of Silverstone, said it wanted proof of Brand Synergy's financial plan before agreeing a deal.
BRDC chairman Ray Bellm told BBC Sport: "We've had a few discussions with Brand Synergy but they have not yet given any indication of their financial backing."
The British GP has been axed from the 2005 provisional calendar.
However, F1 boss Bernie Ecclestone said the race could still be restored to the schedule if the BRDC can come up with an extra £1.5m.
Brand Synergy director Kim Cockburn told BBC Radio Five Live that her company could provide that funding and had agreed a deal with Ecclestone for a seven-year Grand Prix licence.
She added: "We have sent our proposals to the BRDC.
"We share their vision to develop and deliver the masterplan that will make sure that Silverstone stays firmly on the map for the years to come."
Asked if she believed the British Grand Prix's future could now be regarded as safe, Cockburn replied: "Correct."
However, the BRDC says it has not received a formal submission from Cockburn's company - although a meeting is planned for Friday.
"We are very happy to talk to them," said Bellm.
"We have no problem dealing with any partner that has sound financial backing."
A press release from Brand Synergy announcing its plans claims that it is backed by a "major development company".
Mansell is on the board of directors at Brand Synergy, which says it has been working for a year to secure Silverstone's future.
Mansell said: "Silverstone is one of the best circuits in the world for drivers but some of the facilities are not as good as those at new, government-funded circuits like Shanghai.
"We are going to rectify this."
The BRDC confirmed it is making progress in discussions with the East Midlands Development Agency, a government-sponsored body, about securing extra funding from the venue itself.
In the long term, the BRDC wants to sell off parts of the 300-acre site and build a "centre of excellence" to strengthen the UK's motorsport industry, which generates estimated revenues of £5bn a year and employs about 50,000 people.
Jeff Moore, deputy chief executive of the East Midlands Development Agency, told BBC Sport: "We have been working with the BRDC and other parties to see how to release excess land to generate funds.
"They can spend that on upgrading the circuit and maximising the value of the site so they can secure the future of the British Grand Prix.
"By redesigning the circuit they could release large parts of land which could be released for industry."
Moore said his agency estimated that the race itself generated £30-40m for the local economy each year, but there were "many thousands of jobs" reliant on the surrounding motorsport industry.