New Delhi, July 12 - A 22-year-old man, who was arrested Thursday for allegedly killing his girlfriend, committed suicide Sunday in Tihar jail, an official said.

'We received a call in the morning that an inmate (Kapil Sharma) has committed suicide in Tihar Jail. The manner and timing of the act is still not confirmed,' a senior police official told IANS.

Kapil Sharma was arrested after he allegedly murdered his girlfriend Sunita inside her rented accommodation in East Patel Nagar area Thursday night. Sharma suspected she had relations with another man.

Sharma stabbed Sunita to death after the two argued over her alleged affair.

Sharma was preparing for a business management entrance exam while Sunita was pursuing a secretarial course in Delhi.