As many as 16 of every 10,000 subway passengers in the city sneak through without a ticket, a report released by Shanghai Metro said.

With more than 6.7 million passengers commuting by subway daily in Shanghai, freeloaders have caused a considerable economic loss to the company, the report said.

Shanghai Metro would not confirm how much money was being lost, but China Daily estimated it to be about 1 million yuan ($147,000) each month.

So now Shanghai Metro and the subway police have teamed up to stop the increasingly rampant free riders.

The team found 1,770 riders who used fake cards, such as those for senior citizens and disabled soldiers, which entitle them to free subway rides.

As many as 1,840 fake cards were confiscated and 13 fake card producers and sellers were caught.

One man was even found to have slipped under exits at subway stations more than 25 times since June - yet according to subway regulations, which hand out penalties five times the ticket value - the man was fined 500 yuan.

"At rush hour it is impossible to stop those who sneak under turnstiles or use fake cards," said a staff member with Shanghai Metro at Zhongshan Park Station who spoke on condition of anonymity.

"The station is too crowded. If you stop one passenger, hundreds of other passengers behind will complain that their time is being wasted."

"Sometimes I can only watch passengers go beneath the turnstile," he added.

Passengers, on the other hand, said they sometimes avoid buying tickets to save time.

"Sometimes when you are in a rush and you don't have time to queue in front of the ticket vendor, passing under the turnstiles seems to be the only solution," said one man, who admitted he has evaded tickets "a couple of times" at the People's Square Station, the busiest subway station in Shanghai.

Some other ticket evaders complain ticket prices are too high. One woman said she jumps the turnstile almost every day because she cannot afford to spend 300 yuan of her 1,200 yuan monthly income on commuting to work.

The price of a single ticket on the Shanghai subway ranges from 3 to 9 yuan, based on the length of the journey.

Shanghai is not the only city suffering from free riders. In Beijing, some 7,000 single tickets are lost every day, according to reports.