JAKARTA, Jan. 5 (Xinhua) — Australia has expressed regret for humiliating Indonesia's national principle of Pancasila and promised a thorough investigation of the incident which led to Indonesia halting military cooperation between the two nations, Indonesian defense minister said here on Thursday.

Indonesian Defense Minister Ryamizard Ryacudu said that his Australian counterpart Marise Payne had begged apology to Indonesia over the humiliation involving a personnel of Australian Defense Force (ADF) at the military base in West Australia.

Pancasila is the official philosophical foundation of the Indonesian state, with "panca" meaning five and "sila" meaning principles.

Minister Ryamzard said that Minister Payne sent him a letter and called him on Thursday morning, begging for apology over the incident.

"Australian defense minister sent me a letter this (Thursday) morning, begging apology over the incident," Ryamizard said at Indonesian defense ministry.

"Australian defense minister also promised to probe and follow up this case," he added.

Separately, Indonesian Military Commander General Gatot Nurmantyo said that Australian military had also sent him a letter, begging for apology over the incident.

The humiliation of Indonesia's national principle of Pancasila occurred during a joint exercise between Indonesian special unit force (Kopassus) and Australia's Special Air Service in Western Perth, according to Maj. General Wuryanto, Indonesian military spokesman.

Indonesia last suspended military cooperation with Australia in 2014 following the revelation of Australia's spying on communication of Indonesia's former president Susilo Bambang Yudhoyono.