Andhra Pradesh's police chief on Thursday ordered a probe into the incident in Hyderabad in which a suspended police constable took a senior police official hostage for four hours.
Director General of Police Dinesh Reddy directed a senior official of the rank of additional inspector general of police to conduct the probe and submit a report at the earliest.
Earlier, Giriprasad Sharma, a suspended head constable with the Police Transport Organisation (PTO), called on Mr Reddy and apologised for his behaviour.
Mr Sharma told reporters that he took Superintendent of Police Lakshmi Narayana hostage to highlight his problem, corruption and other issues. He made allegations of corruption against senior officials.
He claimed the police chief promised that no case would be booked against him for taking the official hostage.
Mr Reddy also told him that he would be transferred from PTO to state police headquarters.
The four-hour 'hostage' drama ended on Wednesday night when Mr Sharma released the official unharmed after an assurance by Mr Reddy to study his demands.
Mr Sharma said he was suspended by Additional Superintendent of Police Vijaykumar seven months ago without assigning any reason.
"Because of this, I have been facing serious financial problems and mental trauma. There was no other method (other) than this to bring my problem to the notice of the higher-ups," he said.
Mr Sharma kept the police official hostage in a shop run by the constable near Birla Planetarium in the heart of the city.
He had locked the shutters from inside and threatened to kill the official and also commit suicide if police made any attempt to break in.
Senior police officials and firefighters had surrounded the shop.
The incident caused embarrassment to the top brass as the incident took place near the police headquarters.
Police whisked away Mr Sharma after he came out along with the hostage.