Both Israel and Hamas were instructed to conduct internal inquiries after the UN Human Rights Commission adopted a report by Richard Goldstone, a retired South African judge, accusing both of war crimes during the three-week conflict.
More than 1,400 Palestinians and 13 Israelis died in the war after Israel launched a military operation in Gaza in what it said was an attempt to halt Hamas rocket fire on its towns near Gaza.
The UN investigation accused Israel of deliberately attacking civilians, firing white phospohrous shells and carring out torture during the offensive.
"The Israeli operations were carefully planned in all their phases as a deliberately disproportionate attack designed to punish, humiliate and terrorise the civilian population," the report found.
After the report was published, Israel refused to cooperate, although it carried out investigations into individual incidents.
As Israel is no longer a signatory of the statute creating the international criminal court, there is little chance of Israeli officials standing trial before it. The Jewish state has been vehemently critical of the Goldstone investigation.
Hamas was also accused of failing to mount a credible investigation of the allegations.