A key crown witness at the Gordon Wood murder trial denies writing a book to promote his own contribution in "solving" the case, a Sydney judge has been told.
Retired physicist Rod Cross said much of its content was rewritten by editors to make the book more dramatic and to remove science for lay readers.
Mr Wood, whose murder conviction was overturned in 2012, is suing the state of NSW for malicious prosecution in relation to the 1995 cliff-fall death of his then girlfriend, Caroline Byrne.
Associate Professor Cross in 2008 told the jury of his experiments, which led him to conclude Ms Byrne was thrown in a "spear-like" manner from the top of the cliffs at notorious Sydney suicide spot The Gap.
In the NSW Supreme Court on Thursday, Mr Wood's barrister, Bruce McClintock SC, continued his cross-examination of Prof Cross.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
Prof Cross previously denied writing Evidence for Murder: How Physics Convicted a Killer during the murder trial, saying he wrote most of the book on the physics of falling in 2006, put it aside and finished it after the trial.
In a statement tendered to the court, Prof Cross said his main purpose had been to explain how it was sometimes possible to distinguish between an accident, a suicide or a homicide when people fell to their death.
"A second objective in writing the book was to show that physics can be applied in an interesting way to research or investigate even relatively mundane events," he said.
"I did not write the book to promote my own contribution in 'solving' the case."
It was heavily edited and restructured by the publisher and much of the content was not written by him.
"The editors tended to artificially over-emphasise the role I played in the case and omitted much of the physics content," Prof Cross said.
"I take it this was done in order to dramatise the narrative and remove the science for the lay reader."
He also denied claims the purpose of his physics investigation was to convict Mr Wood, saying it was to determine, if possible, how Ms Byrne fell off the cliff.
"I had no vested interest whatsoever in the outcome and I treated everything that the police told me with a degree of scepticism and verified all facts for myself when I could," Prof Cross said.
The trial continues.
