The High Court has overturned a Family Court judgment because of a Western Australian judge's relationship with the barrister of one party during a matrimonial property case.
In a decision handed down on Wednesday, five High Court justices unanimously set aside the judgment of the full Family Court which had dismissed an appeal on the grounds of apprehended bias.
The appellant was a man who started proceedings against his former wife in 2006, a year after they separated, to settle the division of property.
In 2011 a Family Court judge divided the net assets, excluding superannuation, giving 62 per cent to the husband and 38 per cent to the wife, and dealt separately with the early vesting of a trust.
On appeal, the full court set aside the early vesting orders but did not make any consequential orders and the case came before Justice John Walters who in February 2018 made new orders inconsistent with the 2011 orders.
Days later he retired from the bench.
In response to an inquiry from the husband's solicitor, the wife's barrister Gillian Anderson disclosed that while Justice Walters was presiding over the case she'd met him for a drink or coffee about four times, spoken to him over the telephone five times, and exchanged "numerous" and "occasional" text messages over different periods.
But she said her communications with the judge did not concern "the substance" of the case.
"The apprehension of bias principle is that a judge is disqualified if a fair-minded lay observer might reasonably apprehend that the judge might not bring an impartial mind to the resolution of the question the judge is required to decide," Chief Justice Susan Kiefel and the four other High Court judges said.
"Once a case is underway or about to get underway, ordinary judicial practice is that, save in the most exceptional of cases, there should be no communication or association between the judge and one of the parties (or the legal advisers or witnesses of such a party), otherwise than in the presence of or with the previous knowledge and consent of the other party," the justices said, citing a previous High Court judgment.
They found no exceptional circumstances in this case and the communications should not have taken place.
"A fair-minded lay observer" would reasonably apprehend that the judge might not impartially resolve the questions he was required to, they said.
The case was remitted for rehearing before a single judge of the Family Court.