Increasingly concerned that Hamas will steal money donated for Gaza's rehabilitation, the Defense Ministry distributed a document this week revealing that unions affiliated with the terrorist group have set up joint committees with UN agencies that dispense humanitarian aid.

The document was distributed to the Foreign Ministry, Finance Ministry and the Israeli intelligence community, and was also sent to the United States to warn it that the $900 million it has pledged to help rebuild the Gaza Strip could fall into Hamas hands.

"All humanitarian aid sent into the Gaza Strip today needs to receive Hamas clearance," a senior defense official told The Jerusalem Post on Thursday. "Hamas uses violence against international organizations, including UNRWA, if they do not cooperate."

Hamas recently published an ad in a Palestinian newspaper warning that "whoever does not follow its orders will be forced to leave Gaza."

The internal Defense Ministry document revealed that on July 12, a meeting was held between UNRWA, the United Nations Development Program (UNDP) and Hamas officials who are in charge of the contractors and engineer unions in the Gaza Strip.

The objective was to establish a mechanism which will be responsible for distributing the billions of dollars pledged for the rehabilitation of the Strip by the US and European and Arab countries.

So far, Hamas has taken control of millions of dollars transferred monthly by Palestinian Authority Prime Minister Salaam Fayad to the UNDP and designated for Gazans whose homes were destroyed during Operation Cast Lead last winter.

At the meeting, Hamas officials told the UN representatives they wanted to be able to draw up the list of people who would receive the money, according to the Defense Ministry document. The sides decided to set up joint committees and to continue to meet in the future.

"This is an indication to us that there is no effective mechanism that can be established that will bypass Hamas and ensure the money goes straight to the Palestinian people," the senior defense official said.

Israeli government sources said it was "no secret" that UN officials in Gaza were having talks on a technical level with Hamas regarding the distribution of humanitarian aid there.

According to the officials, UNRWA and UNDP had "no choice" but to have some contact with Hamas officials in order for the assistance to be transferred. They added that Israel could live with that situation as long as the talks remained only at the technical level and did not become political in nature.

One official said efforts to develop a mechanism through which money for the rehabilitation of Gaza could be channeled into the region, without in any way strengthening or helping Hamas, is continuing. This effort has been going on since the end of Operation Cast Lead in January, and hundreds of millions of dollars of international aid that has been contributed for rebuilding the Gaza Strip is not being allowed in until such a mechanism is created.

In response to the report, UNRWA Spokesman Chris Gunness released a statement saying: "UNRWA distributes its aid on basis of need. Humanitarian need dictates the way we distribute aid and nothing else."