The person identified as Nitin Longmalai (18) was apprehended from Gaijon village yesterday, Dima Hasao Superintendent of Police Bedanta Rajkhowa said.
Longmali had demanded Rs 20 lakh over phone from Satnam Construction Company of the Dalmiya group at Umrangshu a few days ago, Rajkhowa said.
On the basis of an FIR filed by the company on Thursday, the police yesterday launched an operation and apprehended the person with intelligence input and by tracking his mobile number, he said.
The SP also said that many anti-social elements were trying to extort money in Dima Hasao district.
The police was monitoring the situation and taking all measures to curb such activities, he said.