An elderly was arrested by police for allegedly killing his infant grandson born with a cleft lip in Shanghai.

Born on July 14, the boy died on July 17 at a hospital in Chongming county after being injected with potassium chloride, a prescription drug used with saline in transfusions which could cause the heart to stop when injected directly into the body.

A doctor from the hospital's gynecology and obstetrics department, suspected of providing the man with the drug, was arrested on Monday , thepaper.cn reported on Wednesday.

"The two were arrested for murder," an official from the security bureau in Chongming, told the Global Times Thursday but refused to provide more details.

The elderly admitted he got the potassium chloride from a doctor surnamed Zhou who taught him how to use it before injecting the medicine on the baby's head, according to the report on thepaper.cn.

The hospital's deputy director, Ji Hui, confirmed that Zhou took the potassium chloride from the hospital a few days before the incident.

Ji also said that doctors discovered that the baby had a cleft lip during an antenatal examination in July, but was too late to induce labor. Doctors told the family that cleft lips are curable.

A cleft lip is a congenital split in the upper lip with a mortality rate of 0.16 percent to 0.1 percent.

Every year, 25,000 babies are born with a cleft lip and palate in China, according to data from sohu.com.

Wang Guomin, also a doctor in Shanghai, told thepaper.cn that every year his hospital will operate 2,000 such cases and the operation procedures have become quite mature, with each operation costing around 10,000 yuan ($1,610).

Several non-governmental organizations have been established in China to help cure babies born with a cleft clip.