The defence for Nuon Chea on Tuesday added its support to a long-filed objection – first raised by the defence for the late Ieng Sary – arguing that the Khmer Rouge tribunal has no jurisdiction to try its client for grave breaches of the Geneva Convention, such as torture and wilful killing.

According to the original 2011 objection, the Cambodian law at the time the Khmer Rouge took power placed a 10-year statute of limitations on felonies, and since that window has long been closed, the tribunal has no authority to bring such a charge.

“The 1956 Penal Code sets out a statute of limitations of 10 years for felonies committed in Cambodia,” it continues. “Grave breaches must be considered a felony. As a result there is a 10 year statute of limitations for grave breaches. This 10 year period would have expired in 1989 for crimes which were allegedly committed in 1979.”

Under the principle of non-retroactiveness, a person cannot be charged for an act if the act was not a crime at the time it was committed, and while a UN convention banning statutes of limitations on grave breaches came into force in 1970, it was “not widely ratified” – and certainly not by Cambodia – the Sary defence argued. (Last Wednesday, Sary’s former defence team filed a brief making a similar assertion on behalf of their current client in Case 003.)

In its filing on Tuesday, the Chea defence concurred with the 2011 filing.

Since grave breaches were not part of the Case 002’s first sub-trial, Case 002/01, the court has, to date, never made a definitive ruling on the 2011 objection, court legal communications officer Lars Olsen said.

At the time the objection was filed, the prosecution counter-argued that the “exceptional nature” of grave breaches prevents it from being classified as a mere felony under the Cambodian penal code, and “customary international law” does not provide for a statute of limitations.

“Our position has not changed” since the 2011 response, prosecutor William Smith said in an email.