The chief operating officer of Save the Children is a trustee of an evangelical charity that actively targets Muslim and Buddhist countries in Asia.
Peter Harlock is a senior figure at Save the Children, which describes itself as a secular organisation. But he is also a trustee of OMF, a charity that is dedicated to converting people to Christianity.
Although OMF is involved in aid work, it declares on its website that its primary commitment is to the "urgent evangelisation of Asia's billions".
Japan is one of the countries it highlights as being "poor spiritually".
OMF is also engaged in relief work in tsunami-hit areas, alongside its core projects of "theological training" and "church planting".
Harlock declined to comment. A spokesman for Save the Children denied there was a conflict of interest: "Save the Children is a secular organisation and we do not discriminate in terms of our work, approach and support.
Within our operating guidelines, directors are required to declare interests that are relevant to the organisation. We do not see this as an issue; all Christian charities try to convert people - there's nothing unusual about OMF in that respect."