Former Sydney rugby league player and teacher Chris Dawson murdered his wife and disposed of her body in 1982 because he was infatuated with one of his students, a judge has heard.

Opening the trial on Monday, crown prosecutor Craig Everson SC said Dawson, 73, had called his wife Lynette Dawson a “fat and ugly bitch” and had entered into a consensual relationship with one of his students, known only as JC, repeatedly asking her to marry him.

“He was motivated to kill his wife Lynette by his desire to have an unfettered relationship with [JC],” Mr Everson said.

Dawson allegedly tried to sell his Bayview home without his wife’s permission and briefly moved to Queensland to start a new life with JC before returning to Sydney.

Justice Ian Harrison heard Dawson had contemplated hiring a hitman to get rid of his wife, once when returning from holiday on the Gold Coast in October 1975 and a second time in late 1981 at the Newtown Rugby League Club after a visit with JC.

“JC will testify that when he, the accused, returned from inside … he told her that he contemplated, thought about, getting a hitman to get rid of his wife but decided against it because innocent people would be hurt,” Mr Everson said.

The Crown alleges Dawson eventually murdered his wife around January 8, 1982 but had lied to friends and family members, saying she had called him after that date.

While witnesses claimed they saw Ms Dawson after January 8, Mr Everson said there was no realistic possibility she was alive at that time.

Dawson is accused of having a level of animosity towards his wife about her failure to bear children at the same time as his twin brother, Paul Dawson. The couple eventually had two children together.

The Crown’s case relies on inferences to be drawn from Mrs Dawson’s behaviour, such as commissioning a portrait of her two children shortly before her alleged murder.

In mid-January, Dawson allegedly told the artist his wife had gone away and no longer wanted the paintings. Six weeks after her disappearance, Dawson reported her missing, Mr Everson said.

Also on Monday, the Crown and Dawson unsuccessfully applied to have the entirety of the murder trial and the resultant judgment suppressed temporarily, citing the “media storm” that would emerge.

“Once the evidence gets into the public domain, there is probability, a strong probability, it will be sensationalised in circumstances where this man will be portrayed as an evil murderer, a cunning predator, immoral, etc,” Dawson’s lawyer Greg Walsh said.

Dawson’s previous attempts to permanently put the proceedings on ice failed, with the High Court rejecting this bid in April this year.

The trial is being heard in NSW Supreme Court by Justice Harrison without a jury, after Dawson successfully argued he would be prejudiced if the case was heard by a jury.

Chris Dawson has pleaded not guilty to murdering his wife.

The trial continues on Wednesday.

– AAP