Oxfam refused to ban staff from using prostitutes saying it would "infringe their civil liberties", a training manual has revealed.

The guidance, still available on the charity's website, says that they "strongly discourage" their workers from paying for sex but a total ban would be "impractical".

The same manual reveals that Oxfam has "dismissed staff for exploiting or abusing beneficiaries or members of the local community in virtually every recent humanitarian response".

The document has emerged as the charity faces a growing scandal over its handling of use of prostitutes by its staff in Haiti, where sex work is illegal and some of whom were alleged to be underage.

The charity has since faced revelations of sex for aid and abuse of teenagers in British charity shops.

In guidance, issued in 2006, Oxfam trainers address the issue of why, if they took a strong stance on gender equality, they did not ban sex workers.

Yoma Winder, Oxfam's current global adviser for partnerships and accountability, writes: "We haven't banned the use of prostitutes, but we strongly discourage it. We don't ban it, because we cannot infringe on people's civil liberties, and we know it would be impractical to think we could enforce a total ban.