Surojit Pal, in his mid 20s and an employee of a Salt Lake-based software firm, was arrested on Wednesday by the detective department on the charge of sending obscene email and pictures addressed to a group of women attached to an NGO in the Lake area.

?Pal has been booked under Information and Technology (IT) Act. This is the first time we have applied the act after it was passed in 2000,? said Gyanwant Singh, deputy commissioner of police (detective department).

According to officers of the detective department?s cyber crime wing, Pal, the systems developer of the firm, had sent the first obscene mail to the NGO?s address.

?Before doing so, he pretended to be a person suffering from a number of problems in his personal life and called up the organisation?s helpline. He used to frequently talk to the female counsellors over the phone. But after a few weeks, the women counsellors felt there was something wrong with Pal?s intentions and stopped taking his calls,? said an officer working on the case.

Pal, who did a Master?s in computer science from a Sikkim-based university, created an email account and sent the first mail on January 13. ?He did not use the same mail account to send the second mail with obscene photographs on March 25. He created another account for the second crime,? said Singh.

?Initially, the NGO officers thought one of their employees was involved. But when they could not track him down, they lodged a complaint with us,? he added.

The police contacted the agency that provides Internet service to the NGO. The first mail was checked and the code of the computer used to send the message noted down. It was found that the first mail was sent from a software firm in Salt Lake.