The original NSW licence plate No. 4 sold under the hammer on Monday night for $2.45 million, setting an Australian record.

Chinese-Australian wine collector and sex toy magnate Peter Tseng bought the rare collector’s item before a crowd of 300 people at the 2017 Shannons Sydney Winter Classic Auction, who applauded when the hammer fell on his purchase.

Mr Tseng, who arrived in his red Ferrari bearing the No. 2 licence plate, is a renowned number plate collector, owning the Hong Kong-registered No. 1 number plate and a personalised licence plate “ONE” registered to his 1969 Mercedes in Sydney.

Mr Tseng is understood to have bought the 1910-registered plate from entrepreneur Steve Shelley, co-founder of workforce management software company Deputy and owner of the Burraneer mansion “Nautilus”, which won Australian House of the Year last year.

The No. 4 plates were last seen on Shelley’s dual cab ute before it was registered at the Shannons auction with a guide of $1.2 million to $1.4 million.

After an opening bid of $1 million, bids quickly rose in $100,000 lots between two buyers until Mr Tseng raised his hand at the $1.35 million level. Mr Tseng did not put his hand down throughout the auction, leaving it raised for the next 22 bids until the mystery underbidder – known only as “Ray” – dropped out.

The sale result – at more than $1 million above the highest guide expectations – was the most expensive item sold on the night, which included car memorabilia like the 1920s Michelin Compressor and a 1924 Rolls Royce Barker cabriolet that sold for $123,000. The second most expensive item sold on the night was a 1960 Mercedes Benz Roadster 190SL for $195,000.

The $2.45 million sale result is double Sydney’s median house price and matched the recent sales of a renovated three-bedroom, two-bathroom Victorian semi on Woollahra’s Roslyndale Avenue, and a Californian bungalow also with three bedrooms on almost 600 square metres on Macpherson Street in Cremorne.

Like most single-digit number plates, the No. 4 number plate is known for its ownership providence, most notably when it was registered to the Rolls Royce of Aussie John Symond, founder and executive chairman of Aussie Home Loans.

Sources have come forward to reveal Aussie John sold the plate in late 2015 to art collector and leading Brett Whiteley art dealer Steve Nasteski in late 2015 for about $850,000.​

Mr Nasteski is another well known number plate collector, having bought as many as eight rare two-digit number plates from the late stockbroker Rene Rivkin in 2004 through Nasser Elkordi, an associate of John Ibrahim and former flatmate of radio shock jock Kyle Sandilands.

Despite Nasteski’s penchant for number plates, he sold the No. 4 plate last year to Mr Shelley for between $800,000 and $900,000.

At that level, Mr Shelley would have made a windfall of more than $1.6 million on the number plate in the 18 months he owned it.

Mr Tseng featured in the 2013 Australian documentary film, Red Obsession, narrated by Russell Crowe, which tracked the dramatic rise and fall in the price of French wines between 2011 and 2012.

Monday night’s auction is expected to set a new benchmark in the cost of single-digit plates. Mr Tseng’s purchase of the No. 2 plate set a record at $750,000 that was topped in 2008 when the No. 6 number plate sold for $800,000.

The No. 1 plate is owned by the family of the late founding chairman of Australian National Airways, Sir Frederick Stewart, who had owned it since the 1930s.

In Victoria, single-digit number plates are also investment-grade assets. The No. 1 VIC plate is owned by former Foster’s Group chief Peter Bartels.

In 2013, British businessman Afzal Kahn knocked back £8.5 million for his “F1” numberplate, having bought it for a record £440,000 in 2008, according to The Telegraph in London.