An undated photo of one of Chinese gang leader Liu Han's luxury cars which is put up for auction. [Photo: thecover.cn]

All 13 luxury cars which belonged to Chinese gang leader Liu Han have been sold during an online auction on Sunday, West China City Daily reports.

The former mining tycoon and his brother were convicted of leading a mafia-style gang in southwest China's Sichuan Province in 2014 and were sentenced to death. He was executed last year.

Bidding opened at 9 a.m., with more than a million Chinese netizens followed the auction with closely. Over 1,000 people placed bids in all.

The auction finished at 10 p.m., one hour later than expected due to the volume of bids.

A BMW X5 car initially costing 22,000 yuan (around 3,300 US dollars) was sold for 292,000 yuan. A Lamborghini car saw its value rocket from about 470,000 yuan to over 2 million yuan, while a Rolls-Royce was sold at 3.2 million yuan from an initial estimate of 730,000 yuan.

The low initial prices of the cars were seen as the main reason for the level of interest.

Industry insiders say most of the bidders were small-scale second-hand car dealers and car collection suppliers.