Updated

Swiss prosecutors say they won't open a new investigation into a deal between Angola and Russia that anti-corruption groups say ended up with $750 million missing from Angola's treasury.

According to a 2013 report by Corruption Watch U.K. and an Angolan association of human rights lawyers, the missing money was supposed to go toward repaying a $1.5 billion debt to Russia for help in Angola's 27-year civil war.

The report said Angola paid with promissory notes on future oil shipments, but they went through shell companies that milked much of the money.

A criminal complaint filed by Corruption Watch UK and Angolan citizens alleged corruption by Swiss bank employees and others. Swiss federal prosecutors said Tuesday they found no "new information" that justifies new proceedings. Previous Swiss cases were closed.