The 26-year-old woman from Manipur who was found dead next to her injured partner in south Delhi’s Munirka had at least two stab injuries, apart from the injuries on her neck, according to preliminary observations in her autopsy. Her live-in partner, a 30-year-old man from Manipur who was found unconscious and bleeding from wounds on his neck, is still in critical condition.

The couple was found Sunday night in the bathroom of their rented flat. Preliminary investigation has also revealed the two quarrelled frequently.

The autopsy found that the woman had at least two stab wounds, including one on her chest that punctured her lungs. The injuries to her lungs would have caused her to become unconscious before her throat was slit, senior police officers aware of the matter said on Tuesday.

“The nature of the injuries indicated that the killer attacked the woman with extreme brutality and with intent to kill. We are now waiting for the woman’s final autopsy report to ascertain which stab wound actually claimed her life,” said one of the officers.

A case of murder has been registered under section 103 of the Bharatiya Nyaya Sanhita (BNS) at the Kishangarh police station. However, investigators are still trying to ascertain whether the woman and her partner, who is undergoing treatment at AIIMS Trauma Centre, stabbed each other or if, in a murder-suicide, the man killed the woman before turning the knife on himself.

The man, who runs a grocery shop in the Munirka village, was rushed to the AIIMS trauma centre, where he is undergoing treatment. He was said to be critical and he was on ventilator support, police said.

According to police, the woman was killed minutes after she told her father over the phone about a fight with her partner and said he was attacking her with a knife. Police had said it appeared to be a case of “domestic violence”.

As part of the probe, another officer said, investigators recorded the statement of the woman’s younger sister, who claimed her body after the autopsy on Monday. The sister told the police that the victim had been in a live-in relationship with the man for the past three years.

“It has been revealed that the couple’s relationship had not been cordial for the last one and a half years. They frequently quarrelled over minor issues. The woman had also expressed her desire to return to her native place on several occasions but could not do so. She was not in regular contact with her family; therefore, her family members were unaware of the full extent of disputes between the couple,” added the second officer.