Indonesia suspended cooperation with the Australian military in December for "technical reasons", a spokesman for the Indonesian defense forces said on Wednesday, after offensive material was seen at an Australian training base.

The suspension is the latest in a string of spats between the sometimes uneasy Asia-Pacific neighbors, who have important military ties ranging from counterterrorism cooperation to border protection.

"All forms of cooperation have been suspended," Indonesian military spokesman Major General Wuryanto said. He said a broad range of activities would be affected.

"There are technical matters that need to be discussed," Wuryanto said. Among these issues was offensive training material seen at an Australian military base.

It was "highly likely" cooperation would resume once those issues were resolved, Wuryanto said.

Australia stopped conducting joint training exercises with Indonesian special forces, known as Kopassus, after accusations of abuses by the unit in East Timor in 1999 in the lead-up to the former Indonesian territory's independence.

Jakarta and Canberra have since resumed military ties, citing a desire to cooperate on counterterrorism that became imperative after the bombing of two nightclubs on the Indonesian holiday island of Bali in 2002 that killed 202 people, including 88 Australians.

With ties gradually warming again, the first joint training exercise on Australian soil since 1995 was staged in the northern city of Darwin in September last year.

According to a report in Indonesian newspaper Kompas on Wednesday, the Indonesian military sent a letter to their Australian counterparts warning that cooperation could be suspended and then the head of the country's military, Gatot Nurmantyo, sent a telegram putting this into force on Dec. 29.

An Indonesian special forces trainer had seen training material that insulted Indonesia's founding principles of "Pancasila", which include belief in god, the unity of Indonesia, social justice and democracy, Kompas said.

The offices of Australian Prime Minister Malcolm Turnbull, Foreign Minister Julie Bishop, Defence Minister Marise Payne and Australia’s Department of Defence all declined to comment on the suspension of military cooperation.

Australian media reports said the offensive material was found at Campbell Barracks, an army base in the Western Australian city of Perth. The barracks declined to answer any questions when contacted by Reuters.

Indonesian President Joko Widodo planned to visit Australia in November to cement improving ties, with a focus on economic and maritime cooperation and efforts to counter Islamist militancy, but the trip was postponed amid unrest in Jakarta.

Indonesia last suspended military ties with Australia in 2013 over revelations defense spies tapped the mobile phone of then President Susilo Bambang Yudhoyono.