China`s biggest brokerage, Citic Securities, overstated its derivative business by $166bn (£110bn) from April to September, according to the country`s securities association.
The Securities Association of China said the firm inaccurately inflated the amount of its equity swap transactions in a report submitted in October.
Citic said the error occurred due to a system upgrade and has been corrected.
Probes have resulted in executives confessing to insider trading at Citic.
In September, shares of China`s largest state-owned brokerage slumped after it reported that three executives, including its president, were under police investigation.
The firm has been part of a crackdown by China`s regulators on irregular stock trading since mainland markets plunged dramatically in mid-June.
The securities association, which is partly overseen by the China Securities Regulatory Commission, said it was investigating Citic`s overstatement and would take further action if necessary.
It did add that the error did not affect the month-end net size of Citic`s business.
The brokerage told the Reuters news agency that it had amended the figures at the start of November and the size of its swaps business was $6.2bn.
An equity swap is a type of derivative that refers to a cash exchange between realized gains on specific stocks and fixed interest rates over a certain period of time in the future.
Shares of Citic Securities fell 0.7% in Shanghai.
- Prada seeks younger customers in bid for growth
- Lotte vice chairman Lee In-won found dead
- German business confidence falls post-Brexit, says Ifo
- Tesla touts speed and driving range with new upgraded battery
- Stocks creep up amid Fed limbo, dollar dips leftright 22leftright 12leftright
- China Crinkles Aluminum Foil Makers
- Cisco to lay off about 14,000 employees: tech news site CRN leftright 22leftright
- UK to avoid recession and world economy to ‘stabilise’ as Brexit shock passes - but US poses biggest risk to global growth
- Fuel prices push up UK inflation rate to 0.6%
- Humidity 47%
- Winds 0 kph