A gold mine explosion that killed 10 people and left one missing in east China was caused by illegal storage and use of explosives, as well as improper operations, state media reported Tuesday.

Forty-five people, including 28 public officials, have been held accountable for the January 10 incident in Shandong province's Hushan mine, where a group of miners were trapped underground for about two weeks.

Eleven men from the group of 22 were pulled out alive after a dramatic rescue operation, during which they relied on food and medicine delivered through long shafts drilled by rescue teams.

One miner remained unaccounted for while the other 10 died, and the local Communist Party secretary and mayor were both sacked over a 30-hour delay in reporting the accident.

On Tuesday, state broadcaster CCTV said a provincial investigation found the cause of the blast to be illegal storage and use of explosives, as well as improper work involving fire at the pithead.

Direct economic losses amounted to more than 68 million yuan ($10.5 million), the probe found, while both the company Shandong Wucailong Investment and Qixia city were deemed involved in "late reporting and concealment".

The company's legal representative is among 15 people investigated for criminal responsibility, while 28 officials were given administrative punishment and dealt with internally, CCTV reported.

Companies deemed responsible for the accident were penalised and included in a blacklist as well.