A new book is about to cast dark shadows over Anzac mythology, confirming Australian participation in a massacre of Egyptian civilians previously blamed mainly on Kiwis.

Author Paul Daley uncovered an eyewitness account of the 1918 slaughter of villagers and nomadic Bedouin at the Palestinian town of Surafend in the taped recollections of a trooper of the Light Horse, one of Australia's most hallowed units.

In the tape, held at the Australian War Memorial in Canberra, Ted O'Brien described the attack on Surafend following the murder of a New Zealander by an Arab caught stealing from his tent.

O'Brien said he and Australian comrades had fumed at the "wicked" Bedouin - "you'd shoot them on sight" - downed a good measure of rum and then had gone through the village "with a bayonet".

As many as 120 were killed.

Daley told Fairfax newspapers it was always thought Kiwis were mainly responsible for the massacre. "The Australians' participation was assumed, but never really proven."

The massacre took place shortly after the end of World War I, as the Australian Light Horse, the New Zealand Mounted Rifles and British troops prepared to go home after a long campaign against the Turks.

The Anzac troopers, a combined, fast-moving unit who used horses for manoeuvre but fought on foot, had moved to Palestine after heavy casualties and great praise at Gallipoli.

They waged a hard desert campaign in appalling conditions that was overlooked or talked down in their own countries, where their war was viewed as an easy run compared to Europe's Western front.

High praise of the Anzacs by the chief British commander, Field Marshall Edmund Allenby, and the mythology that has grown up around the cavalry charge and capture of the Turkish stronghold of Beersheba, has for almost a century obscured the Australians' role at Surafend.

Official war historian Henry Gullett had to defy political and military pressure to include a brief reference to the massacre and Australian involvement in his record of the campaign in Sinai and Palestine.

But Australian participation is mentioned in British and NZ accounts.

In a history, former Mounted Horseman Lieutenant A. Briscoe Moore wrote the Anzacs had exhausted their patience with the "treachery of the natives" and that their frustration with their "constant thieving" came to a head when a NZ machine-gunner was shot and killed by an intruder.

Angered further by the failure of British officials to respond adequately, the troops took matters into their own hands.

"Hundreds of men representing every unit in the Anzac division - New Zealanders, Australians and English artillerymen - surrounded the village of Surafend," Moore wrote.

"The native women and children were first put out of harm's way, and then the men, fired by hate ... entered the village, set fire to it, and clubbed the male inhabitants.

"A Bedouin camp situated nearby was treated in like manner."

Daley said the massacre highlighted the moral complexity of war and how otherwise-good men could do terrible things.

"The Anzacs were not the mono-dimensional heroes they have been made out to be," he says, "and they themselves would never have seen themselves like that".