Irfan, who represented Bilari assembly seat, was on his way to attend the marriage of son of senior cabinet minister Shivpal Singh Yadav in Saifai in Etawah district when his vehicle overturned and fell into a ditch on Thursday.
The legislator later succumbed to his injuries. His family has alleged negligence in providing him treatment.
On Sunday, Faheem, son of Irfan met the additional superintendent of police and additional district magistrate and gave an application against the senior doctors accusing them of murder.
"Faheem gave an application against doctor on emergency duty Rajesh Verma, CMS Shashi Kumar Srivastava and one other," ASP Anil Kumar Yadav said.
On Faheem's complaint, an FIR under section 304 of Indian Penal Code (culpable murder) has been lodged at Sadar police station on Sunday night, the ASP said
Earlier, district magistrate Shambhunath had ordered a magisterial inquiry, and directed ADM Ashok Kumar Srivastava to submit his probe report within 15 days.
The DM had said that after a complaint was received in connection with death of the MLA in Moradabad, he conducted a surprise inspection of the Badaun hospital and inquired about the process of admission of critical patients.
Shambhunath said he received complaints that the MLA was administered "injections containing steroid, which led to internal bleeding". He said the cylinder present in the ambulance allegedly did not have oxygen and life saving drugs were missing.
The Bharatiya Janata Party had attacked Uttar Pradesh Chief Minister Akhilesh Yadav, saying his "tall claims" of better health and ambulance services in the state have been exposed by the incident.
Photograph: Samajwadi Party Member of Legislative Assembly Haji Irfan
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