The Peace and Justice law was passed by Congress last year. It gives sharply reduced prison sentences to leaders of Colombia's outlawed right-wing paramilitary factions who demobilize, admit their crimes and turn over any ill-gotten goods.
Last week, the government announced the regulatory norms for the law, to facilitate the arduous task facing prosecutors who are reviewing any crimes by demobilized fighters and tabulating possessions they admitted obtaining illegally.
But the U.N. office of human rights in Colombia said the new norms do not require prosecutors to look for so-called front men whom warlords may have used to buy property to hide their holdings.
In some cases, the front men are unwitting accomplices, said Diana Losada, a U.N. spokeswoman in Bogotá. Still, she said, the law should require that investigators examine each possible case.