Bidding for a pristine Ford GT-HO Phase III was nearing the Australian record price, when the unthinkable happened

Just as the bidding was getting serious in an auction to decide if a Ford or a Holden was the most expensive Aussie car ever, the unthinkable happened.

There was strong pre-auction interest in the GT-HO Phase III

A highly-anticipated auction of some of Australia’s most amazing muscle cars came to a shuddering halt with less than a minute to go, with the Slattery’s auction website crashing as final bids were poised to be made.

A 1971 Ford XY Falcon GT-HO Phase III, previously owned by Perth businessman Chris Marco, whose investment scheme failed allegedly owing at least $240 million to investors, passed the $900,000 mark with about an hour to go until the end of the auction, which was to close at 6pm Perth time on Monday, with extensions should the bidding get heated.

But at 5.59pm the Slattery’s auction site went dark, showing a 504 Gateway Time-Out error instead of eight of Australia’s best muscle cars which were up for auction.

The Phase III had hit the $951,500 mark by this stage, but Slattery Auctions asset manager Steve Waterman said the serious bidders had not even joined the fray.

The company’s IT team was working on the issue, but Mr Waterman said there was no way the auction would be closed out under these conditions.

He said bidders were frantically trying to contact the auction house by phone, but the auction’s end-time would likely be extended until Tuesday some time unless a speedy fix was found.

This GTSR W1 has just 50km on the clock.

Mr Waterman said last week that four serious bidders had been keeping an eye on the Phase III.

The current record price for an Australian-built road car was set in late January, with an orange Holden HSV GTSR W1 Maloo Ute – one of only four ever made - changing hands for $1.03m. Coincidentally, it knocked another Falcon GT-HO from the top spot, with that vehicle selling for $1.03m. The limited edition Maloo was offered to and built exclusively for only four hardcore HSV fans in the lead up to Holden ceasing Australian manufacturing.

In all, eight of Marco’s cars are going under the hammer in the current auction, including a 1977 Holden LX Torana A9X – one of only two to be painted “Super Mint Green”. That vehicle was nearing the $400,000 mark went the website crashed.

A 2017 HSV GTSR W1 and a 2017 HSV Maloo GTSR which still has the factory plastic on the seats and has been driven just 20km were also up for grabs.

Chris Marco’s car collection included some of Australia’s rarest street-legal production cars.

The GTSR W1 – which Mr Waterman said recently was number 206 of a run of just 247, was an example of “the most powerful Holden Commodore ever produced’’.

“The W1, buyers are looking at that and saying it’s the next Ford Phase III, and is in reality rarer than the Phase III.

“What they’re saying is that it’s probably the last petrol-powered crazy car in Australia, as we start to go to electric and hybrid.

“There will be fast cars, but nothing with the noise and the smell.’’

The least expensive of the cars up for auction was a 1975 Datsun 260Z which has just 12,632km on the clock.

That car had a top bid of about $85,000 when the site crashed.

The GT-HO, which has been driven just 17,340 km in 50 years, had been totally rebuilt and was in better condition than when it rolled off the production line, ‘Mr Waterman said.