(Bloomberg News) The U.S. asked a federal judge to throw out claims that the Securities and Exchange Commission should be held accountable for failing to stop an alleged Ponzi scheme by R. Allen Stanford earlier than it did.

SEC officials have legal protection for policy decisions, such as whether to take enforcement action when they suspect wrongdoing, the government said in papers filed yesterday in Dallas federal court.

"Plaintiffs are challenging a policy choice--something they may not do by way of a tort suit for damages,'' the government said in the filing. "Congress did not intend to provide for judicial review of the quality of investigative efforts.''

Eight investors in the indicted financier's Antigua-based Stanford International Bank sued regulators last month for their losses, which amounted to about $18.7 million. They said "negligence and misconduct" by officials in the SEC's Fort Worth, Texas, office let Stanford's activities continue unchecked for years after alarms were raised by agency investigators.

The SEC seized Stanford's businesses in February 2009 on suspicion he was paying above-market rates to early buyers of certificates of deposit by taking funds from later depositors. Stanford, who denies all wrongdoing, was indicted in June 2009 on charges he defrauded investors of more than $7 billion.

The investor case is Robert Juan Dartez LLC v. U.S., 3:11- cv-0602, U.S. District Court, Northern District of Texas (Dallas). The criminal case is U.S. v. Stanford, 09-cr-342, U.S. District Court, Southern District of Texas (Houston). The SEC case is Securities and Exchange Commission v. Stanford International Bank, 09cv298, U.S. District Court, Northern District of Texas (Dallas).