The United Nations refugee agency is sending a team to West Africa to investigate allegations of widespread sexual exploitation of young refugees by aid workers.

The U.N. team will visit Guinea, Sierra Leone and Liberia after a study found evidence that nearly 70 aid workers for 40 agencies have exploited child refugees, mostly girls.

The study, which was commissioned by the British relief group Save the Children and the U.N. refugee agency UNHCR, indicates that aid workers - most of them local - have provided food, medicine, and other services to refugees in exchange for sex.

The initial findings of the study were released Tuesday.

Hundreds of thousands of people have been displaced by conflicts spilling across the borders of Liberia, Sierra Leone and Guinea. Many of the displaced survive only through the help of aid agencies