The former Oxfam country director at the centre of a prostitution scandal admitted to paying for sex at his charity-funded residence during an internal inquiry into the allegations, a report released by the British organisation said today.

Roland van Hauwermeiren, who led Oxfam's team in Haiti, was one of three staff members who resigned over allegations they hired young sex workers following the devastating 2010 earthquake there.

The 68-year-old Belgian has denied organising orgies or visiting brothels in Haiti, saying he told Oxfam he had engaged in "intimate relations some three times" at his home but did not pay for these liaisons.

A redacted copy of a 2011 report from its inquiry made public by the charity said Van Hauwermeiren offered to resign after admitting to investigators that he had hired sex workers at Oxfam-funded accommodation.

"During the interview the CD admitted to using prostitutes in his OGB (Oxfam Great Britain) residence," the report said, referring to the country director.

The charity has faced accusations it was not transparent about the scandal, which has led to the resignation of its deputy head.

The report said Oxfam negotiated a months notice period with Van Hauwermeiren and agreed to allow him "a phased and dignified exit" if he cooperated with the rest of the investigation.

It added that "none of the initial allegations concerning fraud, nepotism, or use of underage prostitutes was substantiated during the investigation, although it cannot be ruled out that any of the prostitutes were underage".

Oxfam has unveiled an action plan to tackle sexual harassment and abuse, and agreed not to bid for any more state funds until reforms were in place.