Richard Falk announced the figure during a press conference in the Jordanian capital city of Amman late on Monday, the Palestinian News Network reported on its website.
Israel has not responded to repeated calls by the UN Special Rapporteur for access to the occupied Palestinian territories.
Due to the prevailing security situation in Gaza, Falk was forced to cancel his visit to the Israeli-blockaded enclave — part of the mandate given to him by the Human Rights Council.
The United Nations says he will visit Gaza later in the year.
Since his appointment in May 2008, Falk has faced hindrances by the Israeli regime, which has refused to cooperate with the rapporteur in his field missions.
In mid-December 2008, Falk was denied entry into the occupied territories by Tel Aviv. He was detained, interrogated and subsequently deported.
The move occurred days before Tel Aviv launched a deadly onslaught against the populated coastal sliver on December 27. The 22-day offensive killed more than 1,400 Palestinians, mostly women and children, injured thousands of others, leveled hundreds of civilian homes and offices and devastated a great portion of the infrastructure in the impoverished territory.