GENEVA, March 4 (Reuters) - The top U.N. human rights official warned on Friday that U.S. officials risked opening a “Pandora’s Box” in the case against Apple Inc that could infringe the rights of millions worldwide and ease the way for authoritarian rulers and criminal hackers.

The Federal Bureau of Investigation obtained a court order last month requiring the company to write new software to disable passcode protection and allow access to an iPhone used by one of the shooters in December killings in San Bernardino, California.

Zeid Ra’ad Al Hussein, the United Nations High Commissioner for Human Rights, said in a statement: “A successful case against Apple in the U.S. will set a precedent that may make it impossible for Apple or any other major international IT company to safeguard their clients’ privacy anywhere in the world.”