An Indian man accused of killing his co-worker told police he did so because the victim introduced him to cigarettes.

Mustakeem Ahmad, 25, was diagnosed with throat cancer likely because of his smoking habit, according to India's Hindustan Times. On Aug. 24, Ahmad went to the restaurant in Delhi's Uttam Nagar area where he and 25-year-old Inayat worked together, picked a fight with Inayat and allegedly shot him dead.

Inayat was an immigrant from Myanmar. He died at the scene after being shot in the back, according to India's Daily Pioneer.

Ahmad had reportedly been previously fired from the restaurant where the two worked. According to police, the pair started as friends but Ahmad became jealous of Inayat over time.

Police told the Hindustan Times that Ahmad started smoking cigarettes and marijuana, allegedly under Inayat's influence. Ahmad reportedly told police this led to a throat infection which was later diagnosed as throat cancer.

Ahmad allegedly planned Inayat's killing, buying a pistol and practicing his shooting with targets. On the day of the crime, police said he told the restaurant's owner — his brother-in-law — to fire Inayat, which he refused to do.

Clint Davis is a reporter for the Scripps National Desk. Follow him on Twitter @MrClintDavis. Keep up to date with the latest news by following @ScrippsNational on Twitter.