The chairman of Oxfam International has been arrested as part of a corruption probe in Guatemala.

Juan Alberto Fuentes Knight, a former finance minister in the country, was detained along with former president Alvaro Colom as part of an investigation into a public bus deal.

The development comes as Oxfam Great Britain is embroiled in an aid worker sex scandal in relation to Haiti.

Oxfam International’s executive director Winnie Byanyima told the Press Association: “Oxfam does not yet know the nature of formal charges, if any, against Dr Fuentes Knight.

“However he has been entirely open with his Oxfam board and executive that he has been among former officials being investigated as part of a budgetary transaction made by the Guatemalan government while he was finance minister.

“He has assured us that he has co-operated fully with the investigation in the confidence he did not knowingly transgress rules or procedures.”