Shortly after becoming High Commissioner for Human Rights I went to Cambodia, where I visited the Tuol Sleng museum in Phnom Penh. Tuol Sleng had been a school, but it became a place of torture and inevitable death for over 16,000 people during the Khmer Rouge period.

I looked at the iron beds with torture implements and saw the graphic photographs of how they had been used. Walking past row upon row of portraits of people young and old, from every walk of life, I could not help thinking back to an earlier visit to Auschwitz. The KhmerRouge, like the Nazis, were impeccable record-keepers - and consummate torturers.

Tuol Sleng also brought home just how much still needed to be done to make human rights a reality. It was horrors like those seen in the killing fields of Cambodia that moved the framers of the Universal Declaration of Human Rights. I have maintained throughout this 50th anniversary year that despite progress since 1948, there is not that much to be proud of.

Possibly no other human rights issue is the subject of as much as agreement as is the need to eliminate torture. The countries of the General Assembly of the United Nations, now meeting in New York, will vote shortly, and probably unanimously, to condemn this abhorrent practice. Yet, as the representatives of many of those countries cast their ballots, some of their fellow citizens back home will be suffering all kinds of degrading treatment or punishment.

In his last report to the Commission on Human Rights, UN Special Rapporteur, Nigel Rodley, wrote that he could only be disappointed at the high incidence of torture around the world. He goes on to list 73 countries where torture is alleged. The list, unfortunately, is by no means exhaustive.

The eradication of torture is one of the priorities of my office. My colleagues in Geneva work closely with the special Rapporteur, providing substantive support and accompanying him on his missions.

The Office also supports the work of the Committee against Torture, the panel of experts that monitors the implementation of the Convention against Torture.

But our work is also carried out where it matters most, on the ground.

UN human rights workers monitor conditions of detention and the administration of justice in a number of countries, thus helping to prevent abuses. And this work is paying off. According to the special Rapporteur, the incidence of torture substantially diminished in some where United Nations field operations were in place following a peace agreement.

Why is torture so common still today? Impunity is at the heart of the problem. Detainees are often left at the mercy of their captors and interrogators, without access to the outside world, thus ensuring that evidence of the crime of torture will not emerge. Authorities also use other methods to manipulate the criminal justice system so as to prevent torturers from being brought to justice. This may be done by passing amnesties or other laws aimed at relieving the perpetrators from criminal responsibility.

The link between torture and impunity is one of the reasons the judgment in the Pinochet case, and the principle of not being able to plead immunity, has struck such a chord among human rights defenders around the world.

The complex nature of the Pinochet proceedings highlights the need for States to ratify the recently adopted Statute of the International Criminal Court, which would pave the way towards consistent, comprehensive and universal prosecution and punishment of international crimes such as torture and help avoid embroiling Governments and domestic courts in difficult complications arising from diplomatic relations.

Mary Robinson is UN High Commissioner for Human Rights