Oxfam faces cutting back some of its overseas aid programmes after warning staff it needs to find £16 million of savings due to the fallout from the Haiti sex scandal.

Freeholds of its charity shops on the high street are set to be sold as part of a bid “to save substantial amounts of money to put [us] on a more stable and sustainable footing”, according to documents seen by The Guardian.

The charity needs to make the savings because of shortfall in its “unrestricted” budget – money raised from its shops and individuals to be spent on whatever it sees fit – suggesting donors and shoppers stayed away after the scandal.

The seven-page document, marked confidential and circulated by circulated last week by the chief executive of Oxfam GB, Mark Goldring, says: “It is clear ... that the size of our programmes will be substantially reduced for this year and next ... this means making tough choices.”

The document said the charity would “sell freehold property to quickly raise substantial funds. This will be done mainly on a sale and lease back basis to preserve our ability to trade from these locations.”