By BBC News Online's Damian Carrington

An online auction for a complete Tyrannosaurus rex skeleton was attacked by malicious hackers on Tuesday who filed 17 false bids.

At least six of these made it through security measures specifically put in place to prevent such action.

"Some people found a way around that process and they have been removed," confirmed Brian Payea, public relations manager for Lycos.

He told BBC News Online: "There are no valid bids so far."

Bank chat

The first attempt to auction the 11-metre fossil dinosaur on eBay was scuppered by prank bids of up to $8m. However, this time, the new auctioneers Lycos Auction had teamed up with the website millionaire.com to try to verify the wealth of bidders before they made their offer.

Mr Payea described what should have happened: "You fill in a form, that is sent to millionaire.com and they review it and have a conversation with your bank. The approval is given and someone can bid."

However, hackers named "mrmanson20", "stevebert" and "dumbass507" found a hole and posted bids of up to $15m, well over the reserve price of $5.8m.

No credit compromise

Mr Payea declined to give details of what happened: "How the whole process works is proprietary and I'm not going into detail about it. But we are very confident it couldn't be done again."

He added that: "The hiccup does not compromise anybody's credit information - that is all encrypted and very secure."

The auction opened on Monday but Mr Payea was not concerned that no verified bids had yet been received: "It takes at least 24 hours for the approval process to be completed. In any case, I think it will take people a little while to commit to that kind of purchase - if it was me, I'd be having a chat with an accountant or two before I bid."

Million dollar bones

Even the reserve price may appear high but in 1997 a T. rex was bought for $8.36m by the Field Museum in Chicago, US. The deal on this skeleton does include delivery from its current home in a Kansas warehouse. However, the bones are only partly exposed from the rock blocks in which they were found.

The 65 million-year-old fossil was discovered on a South Dakota cattle ranch in 1992. Owner Alan Detrich says he sees nothing wrong with auctioning off a piece of the Earth's history.

After all, he said, he spent more than $250,000 of his own money unearthing the dinosaur. And he will give 10% of the proceeds to the owners of the cattle ranch where the rock-encased skeleton was found, he says.

"This auction is open to the world. If we don't have the right to (sell the fossil), then we don't live in America. If we didn't go there and get him, he'd still be up there."

Mr Detrich added that he does not mind if his T. rex becomes a corporate mascot or is sold to a private collector with no intention of displaying it publicly.

Chuck Schaff, at the Museum of Comparative Zoology at Harvard University, said the fossil would be ideal for drawing crowds to a museum, but was probably too expensive for most.

"It's not unethical to sell it, it's just a shame it goes to the highest bidder," Mr Schaff says. "Some specimens do get away from scientists, but that's life. It's sad, though."

The auction, which began on Monday, is due to close at 0100 GMT on 11 February 2000.