The burden of judging the Rayney trial clearly weighed on Justice Brian Martin as he delivered his verdict on Thursday.

The state will appeal Justice Brian Martin's finding that Lloyd Rayney was not guilty of murdering his wife.

The state has launched an appeal against a Supreme Court Justice's finding that Lloyd Rayney was not guilty of the murder of his wife.

Ending what had been dubbed "the trial of a decade'" former Northern Territory Supreme Court Chief Justice Brian Martin earlier this month found Mr Rayney - a former WA prosecutor - not guilty of the high profile murder of his wife Corryn Rayney, a Supreme Court registrar.

Mrs Rayney was found buried in a shallow Kings Park grave in August 2007, sparking a mystery that would enthrall Perth's legal fraternity for more than half a decade.

Lloyd Rayney leaves court after his trial was adjourned until mid-July.

Lloyd Rayney was found not guilty of the murder of his wife Corryn.

With the 21-day window for an appeal against the judge-only decision due to expire within hours the NSW Department of Public Prosecutions - responsible for the prosecution against the Perth lawyer - filed an 11th hour appeal.

The state on Thursday put forward three draft grounds on which it has sought leave to appeal Mr Rayney's acquittal, the Supreme Court of WA has confirmed.

The first ground claims Justice Martin made an error in law by failing to apply a case law principle concerning looking at circumstantial evidence as a whole, rather than in pieces.

The state has also criticised Justice Martin's finding that, even though Mrs Rayney was attacked at or in the area of her Como home, that fact alone did not establish Mr Rayney's guilt.

"The nature of the circumstantial case was that no fact alone established guilt," the draft grounds of appeal reads.

The state also claims the discovery of a dinner party place tag with Mr Rayney's name on it near his wife's grave should have been assessed together with the fact Mrs Rayney was attacked at her home.

This makes up the final draft ground of appeal.

Mr Rayney's lawyer Laura Willox (nee Timpano) said the prosecution's decision to appeal had come as a surprise, although the draft grounds of appeal had not "troubled" the defence team.

"Appeals against acquittals are rarely made," she said.

"We are not troubled by the grounds of appeal.

"Whether the prosecution will even be given leave to appeal is a matter for the courts."

Australian Lawyers Alliance WA president Tom Percy QC said the legal community was widely "shocked" that an appeal had been lodged.

"The general consensus in the legal community at the moment is one of shock and surprise," he said.

"Whilst we always knew it was a possibility I don't think that anyone thought that it was a realistic possibility.

"The judgement to me seemed one which was very sound in law and one which was very comprehensive in fact.

"It seemed to be, and with great respect to the judge, it was entirely correct."

Mr Percy said there was nothing to be made of how late the appeal was filed.

Although the senior Perth barrister has not been involved in the Rayney case, he said the grounds of appeal appeared to centre on both issues of fact and law "in the way that the judge dealt with the issue of circumstantial evidence."

The prosecution's application for leave to appeal would likely now be assessed by a Court of Appeal justice and, if that justice is satisfied the grounds had some merit, it would then go on to the full appeals bench of three justices for hearing.

"Whether or not there will have to be an independent judge brought in to hear the application for leave is a matter that will have to be resolved by the Supreme Court," Mr Percy said.

And the prospect of a retrial would still be "a long way off," he said.

"I wouldn't have thought the thing was likely to be resolved short of about 12 months," he said.

Mr Percy said a defamation case launched by Mr Rayney against the WA Government, which was put on hold pending the outcome of the murder trial, would likely be stalled again by the appeal.

Mr Rayney's ability to practise as a lawyer also remains up in the air after Justice Martin found that the barrister had engaged in "discreditable conduct" by lying to a magistrate, swearing a false affidavit and arranging a phone tap to monitor his wife's calls.

Both the Legal Practice Board and Barristers' Board were reviewing Mr Rayney's privilege to practise law before the appeal was announced.

The WA Bar Association, of which Mr Rayney is a member, could strip him of his membership but it cannot prevent him from practising as a barrister.

The Rayney murder trial cost taxpayers more than $2 million, running for more than three months and attracting unprecedented public attention.

Handing down his verdict this month, Justice Martin was highly critical of police conduct and the prosecution case against Mr Rayney

- with AAP

Rayney murder - The Whole Story