A transporter based in Cooch Behar reportedly received a letter via WhatsApp and a phone call from the suspected Kamtapur Liberation Organisation (KLO) — a proscribed terrorist outfit — and asked to pay Rs 10 lakh to the outfit.

Binoy Das, who owns trucks and runs them in Bengal and Assam, filed a complaint at Boxirhat police station of the district on Thursday. Das is a resident of Najiran-Deotikhata village under Tufanganj-II block of Cooch Behar.

Sources said that on October 14, he got a "letter" via WhatsApp from the outfit, demanding the money.

“As I was busy, I didn’t open the message to see the letter. On October 18, I got a call from an unknown number. I was told that a letter has been sent to me and if I don’t pay the money within three days, they will kill me and my family,” said Das.

The name, Kamtapur Liberation Organisation (KN), was written on the letterhead of the missive, he said.

“In the letter, I was asked to pay up within 10 days but the person who called me said I would have to pay up within three days,” Das added.

The WhatsApp and call numbers were different, he said.

After the phone call was over, Das went to Jorai police outpost, which is under Boxirhat police station, and informed police officers about the letter and the call.

Das also filed a complaint with the police.

Dyutiman Bhattacharya, the district police chief, said they got the complaint.

“We are trying to find out who sent the letter to Das. Our officers are trying to gather details of the number from which the call was made,” he said.