United Nations Headquarters
United Nations Headquarters Thinkstock

The United Nations said Tuesday it was "greatly concerned" after it was cleared for publication that Israel had arrested Wahid Abdallah Borsh, 38, of Jabaliya in Gaza , on suspicion he used his position in the UN Development Program (UNDP), to help Hamas.

The global organization said in a statement that it would conduct an internal investigation into the incident.

"The United Nations Development Program (UNDP) is greatly concerned by the allegation from the Israeli authorities," it said in the statement quoted by AFP, and promising "a thorough internal review of the processes and circumstances surrounding the allegation."

Borsh was charged with diverting aid to Hamas, particularly by using rubble from UNDP projects to build a jetty used by Hamas for its naval force.

He is also alleged to have last year persuaded UNDP managers to focus home rebuilding efforts in areas where Hamas members lived, after pressure from the group.

The UNDP said in its statement that despite the allegations, it was confident it had "robust measures in place to ensure that the rubble, which is removed and crushed, goes to its intended purpose."

"The allegations concerning Mr. Borsh by the Israeli authorities refer to 300 tons of the more than one million tonnes removed, or seven truckloads out of a total of nearly 26,000," it added.

Borsh's interrogation by the Israel Security Agency (Shin Bet) yielded the revelation that in 2014 he was instructed by a senior Hamas official to conduct his work in the UNDP in such a way as to enable Hamas to gain the maximum benefit from it.

Borsh then did various things to help the Hamas. In 2015, he helped build a marina for the use of Hamas's so-called “military wing” in northern Gaza, using UNDP resources.

The investigators also discovered that within the framework of construction project of which Borsh was in charge in 2015, he lobbied his supervisors to give higher priority to areas in which senior Hamas officials lived, as he'd been asked to do by Hamas.

Last week it was revealed that the head of the Gaza branch of the World Vision charity organization had been using his position to transfer funds to Hamas terrorists.

Following that revelation, Australia announced it would cut funding to the group.