The Council of Magical Law appears to be judge and jury of trials of suspected Death Eaters as well as being the council to review information given to them by convicted criminals. The Council of Magical Law could be a subcommittee of the Wizengamot, (Barty Crouch Sr, Albus Dumbledore and Alastor Moody all being members).
Known Accused
Igor Karkaroff, Ludo Bagman, Barty Crouch Jr, Rabastan Lestrange, Rodolphus Lestrange and Bellatrix Lestrange are all known to have been tried before the Council some time after Lord Voldemort's first downfall.