Veteran war crimes investigator Richard Goldstone says his latest mission to investigate possible war crimes by Israel and Hamas is the most difficult job of his long and distinguished career.

The South African judge has prosecuted war crimes cases from Rwanda and Yugoslavia, and has led an investigation into political violence and intimidation in apartheid South Africa. He's now leading a UN fact finding mission into the conflict that erupted last December in Gaza, and has just returned from the commission's first visit to the region.

Public hearings

Expressing his "shock" and "extreme sadness" at what his team saw during their week-long stay in Gaza, Goldstone explained why the commission has decided to hold public hearings as part of their investigation:

"We want particularly to help victims have their voices and faces heard and seen by the international community. I think it's very important for people not simply to read statistics or read stories but actually to see victims. And we want to show what the effects of this violence is on communities. The mental effect it has on children in particular. We want to do that not only in respect of victims in Gaza but also victims in Southern Israel who've been at the receiving end of pretty indiscriminate rocket attacks for some time."

Disappointed with Israel

Although Goldstone has made it clear that the UN team will also investigate attacks on Israel by Gaza-based paramilitary group Hamas, the Israeli government is refusing to co-operate and won't allow the team into the country.

Israel has long accused the UN of anti-Israeli bias and says the Gaza commission's mandate is "intrinsically flawed and defective." But this won't stop the investigation from going ahead, says Goldstone.

"It would have been preferable to have visited Southern Israel and seen the damage with our own eyes and met victims, personally. So it's disappointing from that point of view, but I believe that it will not affect either the completeness of our work or the credibility of the report. Because we're not going to stop and simply say that because Israel's not cooperating we're not going to involve ourselves with the victims in Israel."

Culture of accountability

And for judge Goldstone, challenges such as these won't affect what he says drove him to accept this difficult mission in the first place:

"It was firstly my concern for violations of international human rights and international humanitarian law. We have a new growing culture of accountability. It's very important there shouldn't be impunity for the commission of these crimes and that leaders - whether political or military - should be held accountable. But it was really the opportunity to have an even-handed investigation in the Middle East, which really hasn't happened. That seems to me to be in the interest of all sides. It was really that and my hope that what we are doing can contribute to the peace process."

That hope, Goldstone says, is still alive.