Oxfam has apologised to Haiti's government after its staff was accused of sexual misconduct during a mission after the 2010 earthquake in the country.

"We've communicated that to the minister and we've given as best we can explanations as to what happened in 2011," Simon Ticehurst, Oxfam's regional director, told reporters on Monday, after meeting Aviol Fleurant, Haiti's minister of planning and external cooperation.

"We are open to collaborate as much as we can, in further investigations, as necessary with the Haitian government," Ticehurst said.

Earlier this month, reports surfaced that Oxfam employees paid sex workers while on an aid mission following Haiti's devastating earthquake in 2010.

According to a 2011 internal probe by Oxfam, released earlier on Monday, seven employees left the organisation as a result of the investigation.

Four staff members were fired, and three others, including former country director Roland van Hauwermeiren, were allowed to resign over the allegations, the report revealed.

The internal inquiry also said that a witness during the investigation may have been physically threatened by three of the men suspected of abuse.

Possible cover-up

Fleurant told reporters on Monday that his government was investigating a possible cover-up.

"Oxfam admits the use of prostitutes by their staff in 2011, they admitted with all the evidence," Fleurant said.

"They even used their offices for such activities. Now we are working to see if there was a cover-up, because their report never made it to the Haitian authorities," he added.

The scandal has dealt a devastating blow to the reputation of the organisation, and threatens to complicate the work of other charities.

Oxfam's funding in the UK is currently under review.

On Tuesday, its executives were questioned by UK politicians over the charity's handling of the allegations.

Mark Goldring, the charity's chief executive, said he was "sorry for the damage Oxfam has done both to the people of Haiti, but also to wider efforts for aid and development, by possibly undermining public support".

Goldring also said that the charity has received allegations of 26 new misconduct violations since the scandal broke out. He added that 16 relate to international programmes.