It said that the accused, Hanif Laghari, surrendered to the police after his family members were detained.
To a question about the motive behind the barbaric act of the suspect, SSP Hyderabad Amjad Sheikh said he had stated various reasons, such as being annoyed due to the doctor's alleged misbehavior with him.
According to him, Dr Rathi would often accuse him of stealing fuel, negligent driving, and hurl abuses at him, and wouldn't allow him to visit his family during public holidays.
Laghari said he took the 60-year-old to Ghora Ground, slit his throat with a knife that he always kept with him, and fled the scene.
Police also the statement of the cook, Dilip Kumar could not be corroborated from what was found at the scene.
Meanwhile, CM Sindh Murad Ali Shah, Faryal Talpur, Jam Khan Shoro and other PPP leaders condemned the incident and termed it a blight on the province's spirit of interfaith harmony.
Sindh Hindu Panchayat, too, had deplored the killing of the renowned medic and demanded a thorough probe into it. They had urged police to carryout a multidimensional investigation into the incident.
On Wednesday, police said the incident occurred in Citizen Colony. They said that the dermatologist had retired a couple of months ago and was now running a private clinic in Saddar area.
The LEA then managed to arrest the accused from his hometown of Khairpur using his cellphone record and the account of the witnesses who knew him.