"I can unequivocally state that the shrapnel taken from the child injured in the Gaza beach incident is not a 155 millimeter shell," he said.
The child, Adham, is 12, and was brought to Israel after the incident, where he is hospitalized in the Soroka Medical Center in serious but stable condition.
The IDF took a piece of shrapnel from his body for a lab analysis. The army and the Palestinians have contradictory versions of who was responsible for the explosion, and the argument over who was responsible for the deaths of the family members continues to cause an international storm.
During a briefing held at the Ministry of Defense in Tel Aviv, Kalifi said press reports that two pieces of shrapnel were removed from the teenager were incorrect, and that only one piece of shrapnel was removed.
He added that a lab analysis conclusively found that the shell originated from a source other than the IDF type.
"At this point we cannot say what the source of the shrapnel is; we have a number of different evaluations. There is the possibility that it is a military dud, or a device planted by the Palestinians. Everything is being checked," Kalifi said.
Report casts further doubts
Major General Kalifi added that he met with American expert Mark Garlasco, a military advisor to the Washington-based Human Rights Watch organization. "After talking to him, it became clear that he has no authentic findings," said Kalifi. Garlasco had alleged that an Israeli shell was behind the blast.
Lieutenant Colonel Eren Toval, who commands the IDF's technological division, explained: "We carried out a check for metal and found the explosives that were on it. In total we carried out three independent analyses. The result was that the explosive was standard, but not characteristic with Israeli or American explosives in IDF service, and is not an IDF 155 millimeter shell.
Kalifi said that he did not rule out the possibility that the device was put together by Palestinians out of Israeli shell duds, together with other material, and was aimed at harming Israeli forces.
On Tuesday the Sourasky Medical Center in Tel Aviv has released an unusual statement, saying that that 21-year-old Ayham Ghalia, who was injured in the Gaza beach explosion , was 'cleansed' of shrapnel before arriving at the hospital.
According to new findings, testimonies and hospital records, deadly blast at Gaza beach, which killed Ghalia family members, occurred at time of shelling, not after; British Guardian, Independent, Times newspapers publish findings casting doubt on Israel's claims
The report casts further doubts over what happened in Gaza about a week and a half ago. The Israel Defense Forces said it was not involved in the explosion after completing an investigation it conducted, while the Palestinians continue to claim that explosion was caused by an IDF shell.
Ayham was taken to the Tel Aviv hospital, suffering from a multi-system failure.
She was hospitalized in very serious condition, and was sedated and connected to ventilator.
Ayham regained consciousness, but is still in serious condition. She is suffering from injuries to her hands, legs, and stomach.