One of Britain’s biggest charities last night denied claims it had covered up the reasons behind the departure of senior aid workers, some of whom were accused of using prostitutes in Haiti during relief efforts.

​Oxfam is facing calls to review reports that it let three men resign while four men were sacked over allegations which have emerged about their time in the country in the aftermath of a major earthquake, according to an investigation by The Times.

The charity was part of an international relief effort in the wake of the disaster which killed 220,000 people and left over a million people homeless.

Oxfam said it compiled a report after an inquiry into allegations of sexual exploitation, the downloading of pornography, bullying and intimidation. The newspaper said the confidential report implied children may have been among those sexually exploited by aid workers, although Oxfam said these were "not proven".

None of those accused has been arrested or faced any criminal charges. However, the newspaper reported that executives at the time avoided sacking one of them over fears it could have "serious implications" for the charity's work.