Prostitutes in one of Asia's largest red-light districts have been taking a vocational course to identify the fake currency that they regularly receive from their clients.

The once-a-week training programme in the eastern city of Kolkata, India, is conducted by a non-governmental organisation (NGO) named Durbar Mahila Samanaya, and provides classes for over 10,000 sex workers in the Sonagachi district of the metropolis.

Sonagachi red-light district Kolkata India
Prostitutes in Sonagachi will learn to spot fake currency, which will benefit their own business. Prostitution is illegal in India

The programme is designed to teach them to identify fake notes by touch, and by the sound a note makes when crumpled.

The NGO has also set up an ultraviolet machine in brothels to check for fake notes. Since its installation, the number of fake notes has dwindled by 20 per cent.

Customers apparently regularly dupe sex workers by slipping fake notes under the dim lights of Sonagachi brothels. Seema Fokle, a sex worker, said that customers were handing them more and more counterfeit 500 and 1,000 rupee notes (£6 and £12), damaging their earnings. Some prostitutes in the area earn as little as 100 rupees (£1.20) per day.

Satapadi Jana, one of the trainers in the district, laughed off suggestions that sex workers should report counterfeits to the police: "All the girls are afraid to approach the police for fear of getting arrested. Anyway, who is going to listen to a sex worker?"

Sex workers often do not realise that the currency is counterfeit until they attempt to deposit their earnings with USHA co-operative bank, which was set up by sex workers rejected by government and private banks as undesirable clients.

"It comes to light only when they go to the bank to deposit money," said Bharati, another trainer in Sonagachi.

(Courtesy: Subrata Sarkar, YouTube)

Some sex workers believe that it is mostly first-time customers and illegal Bangladeshi migrants who use counterfeit notes. Recently, Kolkata Police nabbed several Bangladesh nationals for carrying fake Indian currency.

An Oscar-winning documentary, Born Into Brothels, was made on the lives and tribulations of the sex workers in Sonagachi, in 2004.

(Courtesy: infiananant, YouTube)