Ever wondered why it is such a tedious task to get railway tickets booked in Tatkal? Well, here's the answer. The Railways has found the reason behind the perpetual complaints of passengers not being able to get confirmed tickets even after turning up at the ticket counters at 10 in the morning, a time when the Tatkal windows open across India.

An internal probe revealed that 4000 confirmed berths were hoarded by scamsters within a minute if the opening of Tatkal Window, The Indian Express reported.

These touts who sell tickets at a higher price to passengers in need, were exploiting a "facility" in the reservation software. The facility allows someone who has already purchased a ticket to tweak journey details and book another train within seconds at the last moment.

Touts would buy tickets relatively for unpopular trains a day earlier and then exchange them within a matter of seconds for tickets on demanded trains between 10 am and 10:01 am.

"This took seconds," Ajay Shukla, Member (Traffic), Railway Board, told the English daily. "We have now disabled this facility for the first hour after the system opens," he added.

Booking clerks and other insiders were also involved in this multi crore scam. The railway ministry is devising a plan to take action against specific people involved in the scam.

Four arrests have already been made. The accused, identified as Mehtab Khan, Mehboob Malik, Santaram Yadav alias Pappu and P Naga Kumar, have been booked for cheating and criminal conspiracy. They also have violated the Information Technology Act, 2000.

After disabling the facility the railway officials closely monitored the booking patterns around India and observed that instead of 4000 train changes only a few changes were made in the first minute. "We believe those are genuine transactions by passengers altering their journeys," Shukla said.