WWI diggers 'slaughtered German prisoners in New Guinea'

Australian troops in World War I took part in a "mass execution" of German troops following the Battle of Bita Pak in New Guinea, according to a report.

ABC's Radio National Breakfast program will today air a tape recording it obtained of a witness to the alleged slaughter, News Corp says.

The tape was made in the early 1960s by a village elder and discovered only recently, packed away in a box in Queensland.

"On this day, on September 11, in 1914, the Australian Naval and Military Expeditionary Force landed near the town of Rabaul — then the capital of German New Guinea — and captured a German telegraph station," the ABC report will say.

"Officially, six Australians, one German soldier and 30 ­native police died in that battle. The Australians won, but there have long been rumours of the mistreatment and execution of prisoners. Recently, an account by an eyewitness to that battle has been found — and it appears to confirm the rumours."

It is not yet clear how many German troops were allegedly executed or who gave the order to do so.