A gang of workers in China made more than two million yuan (HK$2.5 million) by secretly using a gold-plating bath at an electronics factory and then selling the precious metal.
The technology is normally used to plate electronic circuitry in phones and computers with a thin layer of gold and the workers were caught after the company in Chongqing got suspicious about how few items the equipment was treating, the Chongqing Morning Post reported.
The leader of the gang learned the plating process when he worked in Shenzhen and taught other staff at the electronics plant when he joined the company in 2011.
They put metal chips in a fist-size gauze bag and sank it to the bottom of the gold-plating bath containing a solution of gold particles and chemicals with a heavy weight.
The metal would sometimes be plated with more than 100 grams of gold in one night, according to the report.
The precious metal was then removed and sold.
The gang leader left the company in 2012, but he continued to lead the operation.
He made more than 400,000 yuan in one six-month period, according to the report.
Seven workers used the technique between September 2012 and October last year at the company, which was not named.
The police found that only workers on the assembly line had access to the gold-plating unit so they asked people in the neighbourhood if staff at the plant had been selling the precious metal.
One of the gang who had been selling gold in the area was identified.
Police have recovered about 1.37 million yuan made in the scam, according to the newspaper.