The Gergory Hills McDonald’s where Ms Singh was killed in 2013. Picture: Szilvasi Attila

His extreme actions were therefore a mystery, a coronial inquiry has found.

Findings from the dual inquiry into the deaths of Sandeep Thind and Ranjit Singh in 2013 were handed down in Glebe Coroner’s Court late last week,

Singh, 38, “lost his temper and killed Ms Thind”, 30, by strangling her “for reasons that are unclear” in the toilets of the Gregory Hills McDonald’s in southwest Sydney on August 10, 2013, Deputy Coroner HCB Dillon found.

About a month later, while in custody awaiting trial for murdering her, Mr Singh took his own life.

The couple had argued over what time to start work earlier on the evening of August 9, but she accompanied him to work at McDonald’s to clean the restaurant about 12.21am on August 10.

At 1.08am CCTV footage captured Mr Singh entering the rear female staff toilet cubicle with Ms Thind following.

Once in the cubicle, Mr Ranjit grabbed her around the throat and began squeezing, according to the findings.

Ms Thind said “Why are you doing this? What are you doing this for? Let me go, let me go’, but Mr Singh continued his attack.

When she stopped moving, Mr Singh tried to strangle himself with his jacket, before staff found the pair and forced the door open.

Mr Singh survived and was charged with murder.

The deputy coroner noted that until the time of her death, Ms Thind and Mr Singh appeared “to all outward appearances” to have a loving relationship, with no history of violence.

“Why he acted in such an extreme matter is therefore a mystery,” the report said.

The report did note the only thing known to have caused tension in their relationship was having to leave their then two-year-old child, Momi, in India in the care of Mr Singh’s mother, and the impermanency of the pair’s immigration status in Australia.

Mr Singh’s body was found on September 3, 2013 during a morning headcount by guards at Silverwater’s Mental Health Unit.