An Indian man diagnosed with throat cancer allegedly shot dead the colleague who introduced him to cigarettes.

The accused, identified as Mustakeem Ahmad is said to have been consumed with rage at his co-worker after a doctor attributed the disease to his smoking habit.

Ahmad who was arrested on Friday told detectives that he purchased a pistol and practiced firing it to ensure he killed the victim, who had been working at the restaurant for 18 months.

“Though Ahmad and Inayat were friends at the workplace, Inayat was reportedly better at his job and well-behaved and soon became the favourite of the restaurant owner,” said deputy police commissioner Sibesh Singh.

According to the Hindistan Times, Ahmad started smoking cigarettes and marijuana under the influence of Inayat which led to his throat cancer.

Mr. Singh said: “In the course of time, Ahmad developed throat infection, forcing him to consult a doctor. Ahmad has claimed that the doctor told him he had developed throat cancer due to excessive smoking.”

Ahmad blamed his colleague for his cancer and tried unsuccessfully to get him sacked from his job, he added.

After his work performance deteriorated Ahmad was fired and investigators said he returned to his native village of Amroha in Uttar Pradesh, where he bought a gun and some cartridges.

“He first practiced firing in his village, before returning to Delhi a few days ago,” said Mr. Singh. “He was carrying his loaded pistol to the restaurant and had planned to kill Inayat if he failed to get him fired from the job. That is what eventually happened. Ahmad ended up picking a fight with Inayat. He later shot at him in the middle of the argument,”

Inayat was rushed to hospital but died of his injuries.