Beijing police is investigating the mercury poisoning of a 13-year-old student allegedly caused by a can of Sprite, municipal authorities said Tuesday.

Parents of the boy came to the police claiming their child was poisoned by the deadly chemical substance after drinking an aluminum can of Sprite on Jan. 17, a police officer said on condition of anonymity.

The drink was bought from a supermarket in Tongzhou District, where the remaining Sprite cans had been sealed off by the police, the officer said.

The boy is now discharged from hospital but may have some sequela, including possible infertility, doctors said. The police found a broken thermal meter at the boy's home and is testing it together with the Sprite can, he added.

However, no evidence showed that the thermal meter was directly related to the poisoning by now, he said.

The police had launched a comprehensive investigation on the production, transportation, sales and consumption of the Sprite. It may take some time before the police can reach a conclusion, the officer said.

The police will inform the public of the result once investigation is completed, he added.

This was Beijing's second case of mercury poisoning related to Sprite in less than three months. In November 2009, a man surnamed Zhang vomited beads of liquid mercury right after drinking a can of Sprite in a restaurant. The case remains unsolved.

Officials with Beijing's food safety authorities and industrial and commercial bureau said they were deeply concerned with the case and were waiting for investigation results before taking further actions.

Coca Cola, producer of Sprite, said in a statement Tuesday the company has a stringent quality management system, and its products are safe and in line with China's food and drink safety standards.

Coca Cola inspected all manufacturing equipments and procedures and tested Sprite samples after hearing about the case. No abnormality or disqualification was found, according to the statement.

"Now, we are cooperating with the police in the investigation and cannot give any more comments," the statement said.