They say that Mr. Corzine turned the brokerage firm into an investment bank making risky trades and that he ran the firm in an authoritarian manner and didn’t allow anyone to challenge his decisions.
The firm failed after betting $6.3 billion on European debt that soured.
The House Financial Services oversight and investigations subcommittee is to release the report of its investigation Thursday.
A spokesman for Mr. Corzine did not immediately return a telephone call seeking comment Wednesday. Mr. Corzine told Congress last December that he never intended to misuse customer money, nor ordered anyone to do so.
Legal experts say it could be difficult for the government to build a persuasive case that he did know.
The GOP lawmakers said the panel’s staff interviewed more than 50 witnesses and reviewed 243,000 documents from MF Global, former employees of the firm and federal regulators.
The Republicans said Mr. Corzine acted as the firm’s chief trader in practice, though not in name, and walled off his trading from the firm’s review of its potential risks.
Mr. Corzine rose from the trading floor of Goldman Sachs to become the investment bank’s co-chairman. He then ran successfully for the U.S. Senate in 2000 and later one term as governor of New Jersey.
He stepped down as MF Global’s CEO on Nov. 4, 2011, days after the firm filed for bankruptcy protection.
For months, regulators investigated whether the missing customer money was improperly used to cover MF Global’s short-term needs when its trading partners lost confidence in the firm and demanded cash owed them.
Much of the missing money belonged to farmers, ranchers and other business owners who bought and sold financial contracts with MF Global to reduce their risks from the fluctuating prices of corn, wheat and other commodities.