Bangalore, Feb. 23: The scramble for low-cost air tickets in a booming aviation industry has led to a racket involving pilfered credit card numbers.

The cyber crime cell of Karnataka police busted a network where the racketeers used credit card numbers, sourced from a contact in Mumbai, to purchase tickets online and sold them to those looking for cheap rides.

The police believe that the case is connected to the recent arrest of 11 Nigerians in Delhi who were charged with credit card skimming ? a technique where a reader placed nearby can absorb all card details being used in any ATM machine.

The five-member gang in Bangalore was caught after the police homed in on the servers they were operating from. Three of them acted as delivery boys while the others did the actual transactions.

“The gang bought Kingfisher and Air Deccan tickets that are available only through Internet,’’ a police officer said.

According to the cyber cell, the buyers, often unable to get a cheaper fare than this, got the PIN numbers of the tickets only after paying in cash to the delivery boys.

The cell has already contacted its counterparts in Calcutta, New Delhi, Mumbai and Chennai to know if there are similar cases.

In one particular transaction, 19 tickets were booked for the same flight on February 19. Airline staff got suspicious as many single or small groups of passengers quoted the same PIN number. When the passengers were questioned, they had no answers.

An officer said the onus was on banks issuing credit cards and asked airlines to be alert to the e-fraud.

However, this is not the first such case. A fortnight ago, the police trapped a techie who allegedly used credit card numbers belonging to NRIs in the UK to buy tickets online.

The racket came to light after a couple who made a few trips between Calcutta and Bangalore were detained at Calcutta airport on January 2 for allegedly purchasing tickets with a pilfered card number.

Back in Bangalore, they informed the cyber cell, leading to the arrest of Vikram Solanki. The 22-year-old call centre employee had earned Rs 20 lakh from 1,400 such transactions over 14 months using credit cards issued by UK banks.

John Kuruvilla, chief revenue officer of Bangalore-based Air Deccan, said the airline’s groundstaff insist on checking photo identity cards of all passengers. “Instances of passengers travelling on someone else’s name is very few and far between,” he said.