An assistant sub-inspector posted under the Siliguri Metropolitan Police was arrested by a team of Matigara police on Friday for alleged sexual assault.

Senior police officers said the victim lodged a complaint in July this year based on which the ASI was arrested from Mallaguri area of Siliguri on Friday.

Questions were, however, raised by many Siliguri residents as to why the police took so long in acting against "one of their own".

Sources said that Amar Bir, posted as an ASI in the Bagdogra traffic guards' team, was involved with a woman. In July, she filed a complaint with Matigara police that he was in a relationship with her and had sexually assaulted her.

The police initiated a probe and suspended Bir.

“However, after the suspension, he absconded and went into hiding. Eventually, we could nab him from Mallaguri,” said a senior police officer.

“There was no delay in acting on the complaint," the officer countered. "The investigation was carried out without any bias and the suspended ASI has been arrested,” the officer added.

According to him, Bir has been booked for rape and some other charges.

On Saturday, Bir was produced at the chief judicial magistrate's court in Siliguri.

The court heard the case and ordered a 14-day judicial custody for Bir.