ATIS was an integrated unit composed of Australian and American intelligence personnel and staff from the other Allied Forces (the Netherlands and China) Their primary responsibilities were the interrogation of Japanese POWs from Gaythorne POW Camp and the interpretation of captured Japanese documents. Given the low surrender rate of Japanese soldiers, ATIS placed greater emphasis on document translation. Most of the American personnel were Nisei, second-generation Japanese Americans, trained in the Japanese language.

Tighnabruaich and restored Witton Barrack Pics by Paul Budde June 2024

Interrogations of Japanese POWs took place at “Tighnabruaich,” a mansion in Indooroopilly, Brisbane and the Witton Barracks next door The Nisei interpreters were housed across the Brisbane River in Camp Chelmer.

ATIS expanded, establishing advanced bases in New Guinea in September 1944 and Manila in May 1945, enhancing their operational capacity in the Pacific Theatre.

The Royal Netherlands East Army also participated in ATIS and was represented by Lieutenant Colonel W.A van der Beek. It is unclear if he was heading a group of Dutch military staff.

Melbourne, Victoria. 25 April 1945. Colonel van der Beek, representing Netherlands East Indies Forces at the Shrine of Remembrance during the ANZAC day march (Source: Australian War Museum 008749)

The information on ATIS was abstracted from the website ozatwar.

After the war Van Beek was still in Australia and politically active, as can be seen in the article below.