The former chief investigator of the Khmer Rouge tribunal posed a question to an audience of 50 in Phnom Penh last night: Has the court taken too long?

The lengthy proceedings at the tribunal, which is approaching its 10th year, have been a frequent source of criticism, but according to Dr Craig Etcheson, who worked early on as an investigator in the office of the co-prosecutors for six years, the answer is ultimately “no”.

Speaking at Pannasastra University, Etcheson said multiple factors – including a hybrid common and civil law system that contributed to long investigation and trial periods, as well as the inclusion of thousands of victims’ claims – had seen the tribunal take “much longer than I had ever imagined”.

However, he acknowledged, “experts have said that Case 002 was the largest, most complex criminal case that has ever been brought before a court of law”.

At the end of the day, he concluded, “the Khmer Rouge tribunal has not taken too long. It will take as long as it takes, and it will be worth every single day of attacking the impunity” that allows “monstrous crimes” to go unpunished.

Co-prosecutor William Smith yesterday concurred that the trial’s length was “certainly not excessive” compared to other international tribunals, with prosecution of Nazi crimes still occurring 70 years on.

But Nuon Chea defender Victor Koppe said the trials were initially predicted to last only three years. “It must be the worst managed trial in the history of international criminal law,” he said.