Chinese experts and amateurs are still questioning the claim by China's archaeological authority that an ancient tomb belongs to Cao Cao, a cunning general and ruler some 1,800 years ago.

Yan Peidong, an amateur archaeologist, told Xinhua Wednesday that he has collected evidence showing some of the items excavated from the tomb, in Xigaoxue Village of Anyang, Henan Province, had been purposely forged.

Citing one of his discoveries, Yan, a native of Hebei Province, said he had visited an illegal workshop in Henan where workers admitted they had made fake items for the tomb.

However, Pan Weibin, chief archaeologist leading the authorized excavation project of the tomb, made an announcement on Aug. 27 saying the excavation was conducted using scientific methods and more than 400 items so far found in the tomb were genuine.

He further said he was considering filing a suit charging critics with slander.

Pan also refuted Yan's previous claim that his excavation team had accepted more than 2.3 million yuan (more than 337,600 U.S. dollars) from the Anyang government.

"I have no idea how Yan got that figure. We have never received the money," Pan told Xinhua Wednesday.

"Archaeological research should not be used for the benefit of a certain region. We must be responsible with the history," Yan stressed.

"There are many unsolved mysteries behind the tomb, so it's still early to confirm its identity," said Liu Xinchang, a famous specialist of Cao Cao tomb research.

The State Administration of Cultural Heritage declared in June that the Cao Cao tomb was one of the 10 top archaeological findings in China in 2009.

Cao Cao, a legendary warlord of the Three Kingdoms period (220-280) when China had three separate rulers, has been portrayed as a cruel tyrant, but also a cunning military strategist and poet.