Israel has charged a manager the Gaza office of the Christian relief and development agency World Vision's Gaza with passing millions of dollars to the Palestinian militant Islamist group Hamas.

Israel's Shin Bet security service, said El Halabi diverted around $7.2 million of World Vision money to Hamas each year, NBC news reported Aug 5. That amounts to some 60 percent of the charity's total annual funding for Gaza.

Israel considers Hamas to be a terrorist group.

World Vision said in an Aug. 4 statement it was "shocked" at the allegations against Mohammed El Halabi, who was arrested mid-June and held for 50 days (reportedly without access to a lawyer), IRIN, the news agency that covers emergencies, reports.

World Vision said it had "no reason to believe that the allegations are true." It said that its programs in Gaza were "subject to regular internal and independent audits, independent evaluations, and a broad range of internal controls."

El Halabi was featured as a "humanitarian hero" for the UN's World Humanitarian Day in 2014, but he diverted cash and supplies worth millions of dollars to the military activities of Hamas in Gaza, Israel's internal intelligence service said.

A 2015 evaluation of World Vision's operations in Gaza found that "financial management, supporting accounting and procurement systems and financial reporting were very detailed and rigorous," IRIN reported.

It further praised project managers for getting value for money in procurement.

Israel says the alleged fraud illustrates "Hamas' cynical exploitation of international humanitarian aid." A Hamas spokesman told the Reuters news agency it has "no connection" to Halabi.

Some of the money raised to support injured children in Gaza was diverted to Hamas families by "fraudulently listing their children as wounded," said Shin Bet.

"Money designated for psychological support, education and health in Gaza ... was used to pay the families of Hamas terrorists," the agency said.

"This is a grave incident," Israel's Coordinator of Government Activities in the Territories Maj. Gen. Yoav Mordechai said in a statement, NBC reported.

ISRAEL CALLS ON WORLD VISION TO 'ASSUME RESPONSIBILITY'

Mordechai called on World Vision to "assume responsibility and set your house in order."

The value of the goods and cash allegedly involved is unclear – Israel's statements give a figure of $7.2 million and also say 60 percent of the charity's annual budget was diverted since 2010.

World Vision has operated in Gaza, Israel and the West Bank since 1975.

It's not clear however, how, the figures were arrived at. According to some reports, the allegations are that over $7 million was diverted each year since 2010.

IRIN reported that only fragments of public data are available to gauge the plausibility of fraud and deception on that scale, due in part to what it described as the opaque nature of charity finance.

It said World Vision receives substantial funds amounting to around 82 percent of its US revenue from private individual donations that do not require detailed financial reporting, including church-related fundraising and child sponsorship.

The International Aid Transparency Initiative encourages donors and aid agencies to share data on a voluntary basis, only has one record (a German government donation of $668,922) specific to World Vision's work in Gaza over the last five years.