French prosecutors are investigating accusations that French soldiers in Central African Republic sexually abused children they were sent to protect.

The French probe follows an initial U.N. investigation into the allegations a year ago -- both of which were kept secret until a report in The Guardian newspaper Wednesday forced officials to publicly acknowledge them.

A U.N. worker leaked information about the U.N. investigation to French authorities last year, the U.N. Secretary-General's office said in a statement. That worker, identified by the Swedish government as Swede Anders Kompass has been suspended and is now under internal investigation

The allegations of sexual abuse, and the treatment of the suspended U.N. worker, cast a new shadow on the world body, which has faced accusations of abuses by its peacekeeping forces in the past. They emerged just before U.N. Secretary-General Ban Ki-moon met French President Francois Hollande in Paris on Wednesday.

France sent troops to Central African Republic, one of the world's poorest countries, in late 2013 after it exploded into sectarian violence. The U.N. later set up a 12,000-strong peacekeeping force, and violence has continued.

The U.N. Office of Human Rights in the country's capital, Bangui, carried out a probe after "serious allegations of sexual exploitation and abuse of children by French military personnel," the U.N. Secretary-General's office said.

The alleged abuse occurred before the U.N. force had been established. A spokesman for the U.N. human rights office in Geneva, Rupert Colville, said Wednesday that the U.N. investigation has now been passed on to French authorities.

Paris prosecutor's office spokeswoman Agnes Thibault-Lecuivre said Wednesday the French investigation has been under way since July 2014, without providing further details.

The French Defense Ministry and Foreign Ministry would not comment on the probe.

The U.N. Secretary-General's office said in its statement that the leak of the internal documents did not constitute "whistleblowing" but was a "serious breach of protocol."

Central African Republic has seen unprecedented violence between Christians and Muslims since late 2013. At least 5,000 people have been killed. The U.N. says about half a million people are displaced and another half-million have fled the country.