Sentences for 62 people who defrauded 259 Beijing residents out of more than 80 million yuan ($12 million) were handed down by the No 1 Intermediate People's Court on Tuesday.

The contract fraud case, said to be the largest of its kind in the history of the People's Republic of China, saw lead defendant Shi Shurong jailed for 12 years — the maximum sentence available, according to the judgment.

Fines were issued for 11 of the defendants, who were spared further punishment due to the lesser seriousness of their offenses, the judgment said.

The court, which heard the case over six days in April, found that the crimes were committed in Beijing between 2013 and 2014.

All the convicts worked for a private internet service provider named Zhongwanghuying Internet Co, but they told their clients that the company was run by the Ministry of Industry and Information Technology.

Some of them acted as the company's salespeople, soliciting clients through an online platform and persuading them to buy and register certain keywords said to have great market value.

The clients later found that the registration, as well as the market value, were a sham; but other suspects continued to swindle the clients. They approached those who had registered certain keywords and offered internet services, pretending that the keywords were sought after by well-known companies.

After being told that the keywords would command a higher price after an internet promotion, the clients paid the company a fee hoping to add market value to their websites. Only later did they discover that the business deals were based on lies.