World Vision's global president has questioned Israeli accusations that the NGO's Gaza head diverted millions of dollars in aid to Hamas and said his trial should be open to the public.

A first court hearing for World Vision's Mohammed al-Halabi is set for Tuesday and is expected to be held in secret. Halabi's legal team has appealed.

"A trial is legitimate if it is transparent," World Vision International's president Kevin Jenkins told AFP in an interview.

"So we will have to see how that unfolds. We have got bits of information like everybody else.

"Obviously with such serious allegations against a staff member, we are calling for him to have a fair hearing."

He said the allegations against Halabi were so serious that the NGO was hoping for an open trial to learn as many lessons as possible if they were proved correct.

"As much as our donors want the truth to come out, we want the truth to come out," he said. "Our whole reputation is based on integrity."

Jenkins said allegations that Halabi diverted $7.2 million each year since 2010 to Hamas, the Islamist movement that runs the Gaza Strip, and its military wing were "very difficult to reconcile" with reality.

The NGO has said its Gaza budget for the past 10 years was only $22.5 million, making the allegations all but impossible.

Israel and Palestinian militants in Gaza have fought three wars since 2008 and Hamas is labelled a terrorist organisation by the United States and the European Union.

Charities working in Gaza have some of the tightest controls on funds in the world, partly due to tough counter-terrorism legislation.

The impoverished Palestinian enclave has one of the world's highest unemployment rates and relies heavily on foreign aid.

"We are not a naive organisation. We have world-class systems to prevent the sort of things that are being alleged here," he said.

"They are not foolproof, (but) they would generally have all sorts of red lights going off if anything close to what is being alleged should happen.

"It is very difficult to reconcile those numbers against the controls we have in place."

Jenkins defended the NGO's work in Gaza over the years, saying it had performed "with integrity". Last year, it provided support for more than 40,000 children in the territory, he said.

The NGO has currently suspended its projects in the Palestinian territories pending an internal review, but Jenkins said there was a "strong desire to return to Gaza".

"We can only work in places where we can perform our work with integrity. We feel like we have done that in the past. I feel like we will be able to do it going forward."

Soource: AFP