"Akali Dal president Sukhbir Singh Badal has directed Mayor of Patiala Municipal Corporation Jaspal Singh Pradhan to immediately tender his resignation from the post of mayor in view of the case registered against him," said party secretary Daljit Singh Cheema.
Mr Pradhan was booked by the Punjab Police on Saturday, along with his second wife Paramjit Kaur and son Harpreet Singh after his daughter-in-law Parampreet Kaur was found dead in her house in Patiala on Saturday. All three were booked for murder and conspiracy.
Mr Pradhan had denied that Paramjit and Harpreet were his wife and son respectively. He claimed that she was his friend's wife whom he had been helping.
However, the victim's family claimed that Mr Pradhan had behaved like a father-in-law in the past few years ever since the victim was married to Harpreet.
There were allegations that the mayor tried to hush up the matter initially by passing off the mysterious death of Parampreet as a case of suicide.
Police have arrested Paramjit Kaur and Harpreet while Mr Pradhan continued to be free on Monday.
Taking serious cognizance of the incident, Punjab Chief Minister Parkash Singh Badal on Monday constituted a Special Investigation Team (SIT) under a senior woman police officer, Inspector General of Police (IGP) Shashi Prabha Diwedi, and instructed her to conduct a thorough and impartial investigation.
"The three member team, comprising the IGP, Deputy Inspector general R.K. Jaiswal and Superintendent of Police Balbir Singh, has been sent to the spot and chief minister has directed the team to submit the report at the earliest," a government spokesman said.
The opposition Congress had asked the Akali Dal to come clean on the Patiala incident and not to influence investigation involving the mayor.