China Life was the biggest stock market listing in the world in 2003

The enquiry is focusing on friends and relatives of China Life executives who may have profited from preferential share allocations, the newspaper said.

China Life said it had not yet received any communication from the regulators.

The firm already faces an informal enquiry from US securities regulators and a lawsuit from US investors.

"The company has not received any communication from these bodies," said a spokesman for China Life, referring to the Hong Kong and Chinese regulators.

Officials from the Hong Kong Independent Commission Against Corruption (ICAC) were not available for comment.

$3.4bn listing

The alleged investigation renews fears about management integrity and disclosure which has dampened investor enthusiasm for new share issues in China.

China Life is already in the spotlight.

State auditors found its predecessor company had breached insurance laws.

The insurer said last week that it had received an informal inquiry from the Securities and Exchange Commission (SEC) on "certain matters".

The company also faces a class action lawsuit on behalf of US investors accusing it of failing to disclose the state audit, before its listing, which found accounting irregularities of 4.5bn yuan ($543.48m).

China Life had its initial public offering last December.

It was the biggest stock market listing anywhere in the world during 2003, raising $3.4bn (�1.8bn) in a double debut in New York and Hong Kong.