"German law in this area is leading the world," Peter Weiss, vice-president of the New York-based Centre for Constitutional Rights (CCR), a human rights group, was quoted as saying in Frankfurter Rundschau newspaper on Tuesday.
CCR says German law allows war criminals to be investigated wherever they may be living.
The case, which will be filed at Germany's Federal Prosecutors Office, will charge Secretary of Defence Donald Rumsfeld, former CIA chief George Tenet and eight other officials.
According to Jen Nessel, head of communications and publications at CCR, the group is to present details of its case at several news conferences starting at 1700 GMT on Tuesday.
Abu Ghraib abuses
Fallout from the abuses at Abu Ghraib have continued to resonate in the US and elsewhere since US media first published graphic photographs of Iraqi detainees in various stages of sexual abuse and torture.
Several trials of US soldiers are ongoing, the latest conviction resulting in an eight-year sentence for US Staff Sergeant Ivan "Chip" Frederick for sexually and physically torturing Iraqi detainees at Abu Ghraib.
US Staff-Sergeant Ivan Frederick
(R) got eight years for abuses
At a court martial near Baghdad airport, Judge Colonel James Pohl also sentenced the army reservist on Thursday to a reduction in rank to private, forfeiture of pay and a dishonourable discharge.
It was the toughest sentence in three convictions to date related to degrading abuses at the Abu Ghraib prison.