UN undersecretary-general for peacekeeping Jean-Marie Guehenno. (AFP)

United Nations, Nov. 23 (Reuters): The UN is investigating about 150 allegations of sexual abuse by UN civilian staff and soldiers in the Congo, some of them recorded on videotape, a senior UN official said yesterday.

The accusations include paedophilia, rape and prostitution, said Jane Holl Lute, an assistant secretary-general in the peacekeeping department.

Lute, an American, said there was photographic and video evidence for some of the allegations and most of the charges came to light since the spring.

?We are shining a light on this problem in order to determine its scope, and we will not stop there,? Lute told a news conference.

She did not say if 150 different people were involved but indicated some suspects committed more than one offence.

In May the UN reported some 30 cases of abuse among peacekeepers in the northeastern town of Bunia, where half of the more than 10,000 soldiers are stationed.

Last month, one French soldier and two Tunisian soldiers were sent home, UN officials said. Three UN civilian staff were suspended.

The UN has jurisdiction over its civilian staff but troops are contributed by individual nations. Consequently, the world body has only the power to demand a specific country repatriate an accused soldier and punish him or her at home.

Jean-Marie Guehenno, the UN undersecretary-general for peacekeeping, went to the sprawling central African country, formally called the Democratic Republic of the Congo, last month. He has promised an overhaul of staff discipline.

The UN internal oversight office is expected to release a report soon on the abuse in Bunia. In addition, the peacekeeping department is sending at least two other teams to Congo to deal with various aspects of the problem, Lute said.

Also visiting the Congo within the past month was Jordan?s UN ambassador, Prince Zeid Ra?ad Al-Hussein, who serves as a special adviser on sexual exploitation.

The prince, a former military man, served as a political affairs officer for the UN peacekeeping mission in Bosnia, from 1994 to 1996.

The UN mission in the Congo has some 10,800 peacekeepers and some 60 civilian staff, led by American diplomat William Lacy Swing.

The revelations of peacekeeping abuses is usually kept quiet at the UN until reporters or individual countries disclose the news, as happened in Cambodia in the early 1990s and later in Somalia, Bosnia and Ethiopia. Annan on Friday expressed outrage at the abuse, saying: ?I am afraid there is clear evidence that acts of gross misconduct have taken place.?

?This is a shameful thing for the UN to have to say, and I am absolutely outraged by it,? he said while in Tanzania where Guehenno briefed him.

Annan said the allegations concerned a small number of UN personnel and promised to hold those involved accountable.

?I have long made it clear that my attitude to sexual exploitation and abuse is one of zero tolerance, without exception, and I am determined to implement this policy in the most transparent manner,? Annan said.