Police in Hanoi Thursday placed the staff of a local petrol station under investigation for suspected involvement in the capital's huge petrol scam busted in July.
Hoang Van Quy, 31, a sales clerk at Hoang Xuan Loc Station in Tu Liem District, was accused of "cheating customers," police said.
Previously police had taken 54-year-old Nguyen The Loc, who ran the station, and his employee Nguyen Tuan Quang, 31, into custody on the same charges.
Initial investigations show that Quang supplied an illegal electronic chip to Loc and helped him install it in the station's pump systems.
The modified systems helped Loc earn about VND1,200 (US$0.06) extra on every liter of fuel he sold, which was the largest illegal markup detected so far in Hanoi, police said.
Between April 20 and July 27, 2010 the pump cheated customers out of some VND400 million ($20,544), according to the police.
They said further Investigations into the fraud were ongoing.