BEIJING (Reuters) - Chinese authorities are investigating a senior policeman in the Inner Mongolia region for his role in the wrongful execution in 1996 of a teenager, who was exonerated this week for the rape and murder of a woman, state media said on Thursday.

Thousands of people have in recent days urged the government to investigate and punish the officials responsible for the wrongful conviction of the young man, Huugjilt.

On Monday, a retrial by an Inner Mongolian court found that Huugjilt, then 18, was wrongly convicted of raping and killing a woman.

The Xinhua state news agency said prosecutors were investigating the deputy director of the Hohhot Public Security Bureau, Feng Zhiming, on suspicion of "crimes committed in duty".

Feng, who led the task force investigating Huugjilt, was not available for comment.

Another man confessed to the murder in 2005, but a retrial was not conducted until this year, the official Xinhua news agency reported.

China has embarked on legal reforms, including reducing the use of the death penalty, as public discontent mounts over wrongful punishment.

The decision to exonerate Huugjilt on Monday was the most talked-about topic on Sina Weibo, China's version of Twitter, with 84,000 comments.

While wrongful executions have often stirred outrage, capital punishment itself has wide support from the public.

Anti-death penalty campaigners say China uses the death penalty far more often than other countries. The government does not release the number of executions it carries out, deeming it a state secret.