Jeff Gindin, who represents Seraphim Storheim, filed a notice of motion asking that the new evidence be heard when the case appears before Manitoba's Court of Appeal on Friday.
In court documents, Gindin says the evidence relates to the victim's visit with Storheim and Storheim's relationship with one of the defence witnesses, Connie Kucharczyk, who helped Storheim entertain the boy during his stay.
"The aforementioned evidence could reasonably, when taken with other evidence adduced at the trial, be expected to have affected the outcome of the trial," Gindin wrote in a motion filed Oct. 17. "The evidence was not available by all due diligence at the time of the trial."
Gindin declined to comment further about the new evidence. The Crown also declined to be interviewed.
Storheim was convicted earlier this year of sexually assaulting a boy who had come to visit him in Winnipeg in 1985.
The man testified that during that visit Storheim would routinely walk around naked and would sometimes lie naked on the floor and touch himself. The man testified that another time Storheim touched him and inspected his groin as he sat naked on a bed.
Storheim testified he talked to the boy about puberty and inspected his pyjama bottoms at the request of the boy, but denied anything inappropriate took place.
The 68-year-old was sentenced to eight months in jail but has been free on bail pending his appeal hearing. Justice Christopher Mainella, who presided over Storheim's trial, now sits on the Court of Appeal.
In his original appeal notice filed in July, Gindin said he was appealing on numerous grounds. The conviction "is contrary to law, evidence and the weight of the evidence," Gindin wrote.
Mainella should have given greater credibility to Storheim's evidence and should not have dismissed Kucharczyk's evidence "due to bias" that did not exist, the defence lawyer suggested.
He also challenged the eight-month sentence handed to Storheim. Gindin had argued for no jail time, because Storheim's reputation had been ruined and he didn't have a criminal record.
"The sentence imposed was harsh and excessive having regard to the age, background and circumstances of the offence," Gindin wrote.
Storheim was a priest in the Orthodox Church in America but he later rose to archbishop — the church's highest-ranking cleric in Canada. He was placed on leave when he was arrested in 2010 and retired following his conviction.
The Orthodox Church in America has 700 parishes, missions and other institutions across North America. It is separate from other Orthodox churches such as the Greek Orthodox Church and the Ukrainian Orthodox Church.