The police picked up Satya Prakash Shukla as a suspect on Tuesday morning and he died hours later.
According to reports, the UCO bank branch is located on the ground floor of Shukla's house and the loot took place when the bank officials were coming out of the branch with the cash.
Superintendent of Police Amethi, Khyati Garg, said that according to information, Shukla had given the tip off about the cash being carried by the bank officials.
"We called him and he came with his two sons to the police station, After some time, he complained of uneasiness and was taken to the community health centre in Bhadar. The doctors said that he had consumed poison and referred him to the district hospital where he died," she said.
The SP said that Shukla had told his sons about having consumed poison. She insisted it was not a case of custodial death.
"We have got some clues about the bank loot and we will solve the case soon," she added.
Shukla's family, however, said that he was beaten by the cops which led to his death.
A large crowd gathered at the district hospital where Shukla's body has been kept in the mortuary.
A heavy deployment of police has been made on the spot to prevent any untoward situation.
( With inputs from IANS )