The accused has been identified as Himanshu Maurya, a resident of Krishna Nagar in Kanpur.
According to police, the SSP office had received a complaint on December 3 from two persons stating that a message was received by them on their mobile phones wherein the sender had threatened to kill Adityanath and Khattar.
On the basis of the complaint, a case under relevant sections was registered and an investigation was taken up under the supervision of SSP Anant Deo.
"ATS, STF and cyber cell sleuths were roped in to achieve a breakthrough at the earliest. After preliminary investigations, and with the help of technical inputs, the sender's location was traced to Krishna Nagar in Chakeri area of the city. The team searched the locality and finally nabbed the accused," the SSP said.
The mobile phone used to send the threat mails has been recovered. It has been sent for cyber forensic analysis.
SP (Crime), Rajesh Yadav, said that during interrogation, Maurya claimed that he had done his masters in commerce from Chhatrapati Shahuji Maharaj University (CSJU), Kanpur.
"He first tried to dodge police saying that he is mentally disturbed, but during sustained grilling, he broke down and confessed to his involvement in sending death threat message to his two old friends Arpit Tripathi of Krishna Nagar and Ambrish Shukla of Patel Nagar," the SP said.
Earlier, also, he had been arrested for sending indecent messages to a woman from Haryana.
"Following a complaint by the woman, he was arrested and then sent to jail. Later, he procured bail in the matter," the police officer said.
( With inputs from IANS )