A woman faces trial charged with making about 20,000 yuan (US$3,000) from three people with rigged prepaid shopping cards, Shanghai police said yesterday.

The suspect, surnamed Lu, confessed to scratching off the original silver ink covering the PIN on the back of cards, writing down the numbers and then covering the numbers up again before selling the cards to dealers, police said.

One of the victims was a man surnamed Ni who was running a “gift-dealing” shop. Ni said he paid 930 yuan for each of eight cards with face value of 1,000 yuan from the woman after making sure that the silver ink over the codes was intact, but then he found out that there was no money on the cards.

The cards were “OK cards” issued by Bailian Group.

Police in Pudong said the cards had money in them when Ni purchased them from the woman.

But all of the money was used up to charge seven gas cards about 50 minutes after the deal was made.

Police tracked her down because she had used her national ID number to buy the gas cards.

The suspect, whose age was not given, is accused of involvement in two similar cases.