He wrote numerous books, including The Sundowners (1951), a portrait of a rural family in the 1920s as they move from one job to the next, and The High Commissioner (1966), the first of a long series of popular detective stories featuring Sydney Police Inspector Scobie Malone.

"[3] However he added that "the night after we were repossessed, our friends turned up with chairs, an old table, cakes, sandwiches – they were all battlers but they helped out.

He spent the following eight years doing a variety of jobs, notably as a commercial artist for Austral Toon under Eric Porter.

[5] Cleary enlisted in the Australian army on 27 May 1940 and served in the Middle East before being transferred to the Military History Unit.

Cleary's first novel was the 1947 work, You Can't See 'Round Corners, about the life of an army deserter wanted for the sensational murder of his girlfriend in wartime Sydney.

Cleary started writing this in the army and finished it on board a ship en route to London where he had hoped to find work as a screenwriter.

He had time for script work, contributing to the screenplay for Damon and Pythias (1962) and writing an un-used draft for The Diamond Smugglers.

The High Commissioner (1966) introduced the world to detective Scobie Malone although initially it was meant to be a stand-alone book.

Cleary followed it with The Long Pursuit (1967), set during World War II, originally written as a film script.

"[15] Cleary said 50% of his screenplays had been filmed by that stage and that he had recently turned down $50,000 to write a TV series set in the South Pacific.

He wanted to write about the Opera House so Scobie Malone returned for Helga's Web (1970), which was later filmed (Cleary wrote a script which was not used).

Cleary returned to Scobie Malone for Ransom (1973), set in New York, but then stopped writing about the detective as he did not wish to be trapped as a writer.

He did Peter's Pence (1974) a thriller; The Safe House (1975), about World War II; A Sound of Lightning (1976), set in Montana.

Vortex (1978) was about tornados; The Beaufort Sisters (1979), about sisters from Kansas; A Very Private War (1980) was about coastwatchers in World War II; The Faraway Drums (1981) was about a plot to assassinate King George V; The Golden Sabre (1982) was set during the 1917 Russian Revolution; Spearfield's Daughter (1983) was later filmed as a mini series; The Phoenix Tree (1984) was set in Japan during World War II; The City of Fading Light (1985) was set in 1939 Berlin.

[5] Writing the Scobie Malone series of novels enabled him to tell Australian stories which appealed to an international audience, and he remained popular with readers throughout his career.

Malone returned in Dragons at the Party (1987), about the Australian Bicentennial, then was in Now and Then, Amen (1988), Babylon South (1989), Murder Song (1990), Pride's Harvest (1991), Dark Summer (1992), Bleak Spring (1993), Autumn Maze (1994), Winter Chill (1995), Endpeace (1996), A Different Turf (1997), Five Ring Circus (1998), Dilemma (1999), Bear Pit (2000), Yesterday's Shadow (2001), The Easy Sin (2002) and Degrees of Connection (2004).

He published three more novels, all set in Australia: Miss Ambar Regrets (2004), Morning's Gone (2006) and Four-Cornered Circle (2007), then retired.