The man claimed that he also stabbed his own neck and later his stomach, police said.
A 36-year-old Israeli woman was on Thursday found dead at her residence in this southern Kerala district, police said.
Police suspect that the woman's 70-year-old live-in partner killed her and have lodged an FIR under section 302 of the IPC against him.
An officer of Kottiyam police station narrated the statement given by the man, who claims to be a yoga 'acharya', that the couple decided to commit suicide and as part of that, the woman slit her throat.
The man claimed that he also stabbed his own neck and later his stomach, police said.
However, the woman had several stab wounds on her body besides the fatal injury to her neck, it said.
The man was also booked under section 309 (suicide attempt) of IPC and is presently hospitalised and under police surveillance, the officer said.
The incident, which occurred on Thursday afternoon, came to light when the accused's relative found the couple in their room in an injured state.
As the relative shouted for help, the man, who was still conscious, got up and shut the door, police said.
The door was broken down after police arrived, but by then the woman was dead, the officer said.
The couple were living in the house of the accused's relative, police said.
The woman had been in Uttarakhand for 15 years and was in Kerala for the last one year, he said.
According to the accused, the woman was depressed and despite yoga lessons from him, she was not feeling better, the officer said.
The accused claimed that he was suffering from psoriasis and did not want to continue to live and hence, the couple decided to end their lives, the police said.
A suicide note was found in the room, but it has not been analysed yet, the offier said.
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