Three Ho Chi Minh City gas station employees who short-changed numerous drivers with a magic-like trick have been sacked, but police have said they need official complaints in order to initiate legal proceedings.

Nguyen Dac Hoang Long and Tran Phuoc, who both worked at Filling Station No.1 at 220 National Highway 13 in Binh Thanh District, and Ha Van Thanh, from the 27-7 pump station at 624 Kha Van Can Street in Thu Duc District, were all fired, their employers confirmed on Tuesday.

The decisions came after managers of the two filling stations watched videos filmed by undercover Tuoi Tre (Youth) newspaper reporters, showing the dishonest pump attendants cheating their customers by using ‘magical hands.’

When returning change to drivers, the con artists would count the banknotes slowly, but would secretly keep the last bill with their concealed fingers when they actually handed the money to the customers.

The trick works best when a customer pays a VND500,000 (US$22.32) bill for VND50,000 worth of gasoline.

The dishonest pump attendants would count four VND100,000 ($4.46) banknotes and one VND50,000 bill slowly in front of the customers, then rapidly retain the last VND100,000 banknote when giving them the change.

Using the trick, Long was able to steal up to VND1.5 million ($67) from customers on a daily basis, and even on his ‘unlucky’ days, the ruse still earned him as much as VND400,000 ($17.86).

Vo The Chang, manager of the 27-7 pump station, said that after sacking Thanh, he had also asked his other employees to guarantee that they would not cheat customers.

Chang added that Thu Duc police had come to the station to verify Thanh’s actions.

Le Anh Tuan, the Thu Duc police chief, confirmed to Tuoi Tre on Tuesday that his officers were investigating the case, as unearthed by the newspaper’s footage.

However, Tuan encouraged victims of the dishonest pump attendants to speak out, “so police have grounds to handle the cases.”

In a separate video filmed by Tuoi Tre, Long revealed that the trick was widely known among pump attendants, meaning customers are unknowingly being short-changed at multiple filling stations across Ho Chi Minh City.

It is advised that people avoid paying for their petrol refills in high denomination banknotes, and always check their change before leaving.