Oxfam chief says sex-abuse claims shame the organization

The head of Oxfam International says claims that staff members sexually exploited people in crisis zones are "a stain" that shames the charity.

Executive director Winnie Byanyima says she is appointing an independent commission to investigate the allegations, and is urging victims of abuse to come forward.

She said Friday that the commission will "look into our culture and our practices" and set up a vetting system for staff.

U.K-based Oxfam has been rocked by allegations that senior staff working in Haiti after the country's 2010 earthquake faced misconduct allegations including using prostitutes and downloading pornography.

Oxfam says it investigated, but it has been accused of a cover-up.

Byanyima told the BBC that "what happened in Haiti and afterwards is a stain on Oxfam that will shame us for years."