The U.S. Department of Justice Tuesday said it wants to drop a massive foreign bribery case born from a sting operation that netted nearly two dozen, but has yet to produce a single trial conviction.

A January 2010 FBI sting busted 22 businessmen for allegedly trying to bribe a defense official for an African country. The trials resulted in two deadlocked juries and three acquittals.

After the Justice Department carefully considered the outcome of the first two trials, prosecutors asked a federal judge to drop the indictments against 16 of the remaining defendants. The department also blamed key court decisions on evidence that would have hamstrung prosecutors in future trials.

In light of all the foregoing, the government respectfully submits that continued prosecution of this case is not warranted under the circumstances, the Justice Department wrote in a two-page court filing.

The case was brought under the Foreign Corrupt Practices Act, a Watergate-era anti-corruption law banning companies based in the U.S. or on a U.S. stock exchange from bribing officials in other countries.

The Obama administration has dramatically stepped up enforcement of the FCPA, accusing major companies and their executives of hatching elaborate bribery schemes in foreign countries for lucrative business deals. Under Obama, the Justice Department has scored eight of the 10 largest settlements in the history of the law and charged more than 50 executives and employees with FCPA violations.

These cases rarely go to trial and settlements are frequently negotiated, given the potential for bad headlines and uncertain legal terrain.

The Las Vegas sting case, the largest investigation and prosecution in the history of the FCPA, was one of the few that made it to trial.

The case centered on a scheme to bribe an FBI agent posing as an aide to the defense minister of Gabon. The 22 defendants, three of whom pled guilty, were executives and employees in the military and law enforcement industry.

Prosecutors said the defendants had agreed to pay a 20 percent commission to the Gabon defense minister's aide in order to score a $15 million deal to outfit the presidential guard. The defendants were allegedly told that half of the 20 percent bribe would go to the defense minister.