At least six Chinese judges are being investigated for corruption which was thought to have led to the loss of over 40 lives in a mine blast in central China's Henan Province, local authorities said Thursday.

Zhang Guoqing, president of the Yichuan County People's Court in Henan, and five other judges, were in police custody to face a charge of taking bribery, the Henan Provincial People's Higher Court said in a statement.

They were accused of taking bribes from mine manager Wang Guozheng to give him a lenient verdict in September last year. Wang was then sentenced to one year in jail with an one-year reprieve for cover-up of a gas leak that killed two miners on May 1, 2009.

According to two regulations issued by the State Council, China's Cabinet, Wang should not be a legal representative of any coal mine in five years after the court verdict.

But during the reprieve period Wang, still as head of the mine, continued illegal production for almost a year after local work safety authorities ordered the mine to suspend operation for the gas leak.

A powerful blast at the poorly-managed mine on March 31 left 44 dead, four missing and two injured. Wang Guozheng fled immediately after the accident, but later surrendered to police.

Investigators blamed illegal operation and insufficient safety supervision as major causes of the blast.

More judges in the county could be investigated as the probe deepened, according to the statement.