The Delhi Police has arrested a 29-year-old Bangladeshi national from Kolkata for allegedly sending a hoax e-mail to the Delhi airport about an explosive in a Kolkata-bound flight, officials said on Monday.

Mohammad Nazrul Islam sent the e-mail so that the flight would be cancelled and his brother-in-law not reach Calcutta to meet him, the police said.

"On February 27, a complaint was received from the Delhi International Airport Limited security officer at IGI Airport police station. The complaint alleged that a threat e-mail was received about someone carrying explosives and a request made to check every bag and luggage," Deputy Commissioner of Police (IGI Airport) Usha Rangnani said.

Based on the information, the airport was put on high alert and a full emergency declared. The threat e-mail was later found to be a hoax. During investigations, it was found that the the accused created a new e-mail address to send the mail.

"We checked the WiFi (used to send the e-mail) and the connection was found to be that of a hotel in Kolkata. At that time, 40 guests were staying in that hotel and all of them were using the same WiFi. Almost all of them were Bangladeshi nationals," Rangnani said.

The police said the details of the 40 people were checked and it was found that one person -- Amardeep Kumar -- had come to the hotel to meet his relative after taking the Delhi-Kolkata flight mentioned in the e-mail.

"On interrogation, he said he had gone to the hotel to meet his brother-in-law Islam, who had been staying there for almost a month," Rangnani said.

"Islam's phone was physically examined but he had deleted its entire history Islam admitted to his guilt after being grilled by the police and disclosed that he had sent the e-mail to get the flight cancelled as his brother-in-law was coming to meet him and he did not want him to reach Kolkata," she added.

Islam was brought to Delhi on a transit remand and arrested for sending the hoax e-mail.

The officer said Islam revealed that he had done an aviation course. He also disclosed that he had been staying in India to avoid lenders in Bangladesh as he is under huge debt.

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