Online auction site eBay says it has intervened in the sale of a former RAF nuclear bomber after bogus bids of more than £7m were made.
The plane was bought 21 years ago
An eBay spokeswoman said recent bids of five figures were genuine, after earlier high bids were proved hoaxes.
She added that the site had recommended seller Brian Bateson to use its "pre approved bidder protection" which allows bidders to be vetted.
The Cold War relic, bought 21 years ago, is based at Blackpool Airport.
The XL391 plane belonged to the RAF before it was bought 21 years ago by pilot Mr Bateson.
He set a reserve price of £6,000 but the bids suddenly rocketed to the millions prompting the site to investigate the "suspicious" increase.
"eBay has contacted the seller of the Vulcan bomber to advise them to use eBay's pre-approved bidder protection, recommended for expensive or high profile listings," said an e-Bay statement.
It added: "Pre-approved bidder means that sellers can vet bids and create a pre-approved bidder list for their items."
The site also said that once a user places a bid, it acts as a binding contract, and the bidder is obliged to honour it.
Hoax bidders are warned after their first bogus bid, with a similar warning if a second hoax is offered.
They are banned if they commit a third offence.