The Alberta premier says he requested that Denis resign after learning over the weekend that legal proceedings had started between Denis and his wife, Breanna Palmer.
Records show a private hearing was held at Calgary Court of Queen's Bench on Friday but a publication ban was placed on the evidence.
A request by the media for more information on the case was rejected by the court.
"This was a private hearing and a statutory access and publication prohibition order has been granted by a judge of the provincial court of Alberta," wrote Richard O'Gorman, assistant chief judge of Calgary Family and Youth Court.
Prentice told reporters Monday that, under the circumstances, it wasn't appropriate to have Denis stay on as justice minister.
"I think this is a private matter between him and his spouse. It's not appropriate for anyone to serve as the minister of justice and the attorney general when they have legal proceedings or are a party to legal proceedings that are before the courts," Prentice said.
"The minister of justice and the attorney general are responsible for the administration of justice and he cannot be a private litigant at the time he serves as the minister."
Prentice said he is comfortable with Denis continuing as the PC candidate for Calgary Acadia.
"I have confidence in him as a person and he will press ahead as our candidate."
Denis has not spoken publicly about his situation, but issued a statement on Saturday.
"My wife and I have had difficulties in our marriage over the last several months. I am very saddened by these recent circumstances,'' he said.
"This is a very difficult time for my family, and I would ask for respect for our privacy on this matter while it's being resolved.''
Denis agreed it wouldn't be appropriate for him to continue as justice minister while the matter is being handled.
NDP Leader Rachel Notley, speaking to reporters Monday in Edmonton, said it was appropriate for Denis to leave his post, but questioned the timing.
"It is true that it's not appropriate for someone who is the subject of a personal legal battle to be in the position of attorney general," said Notley.
"I don't know exactly when the legal dispute officially commenced in relation to when he stepped down from being the attorney general, but certainly it would be troubling if his tenure as attorney general extended into the time when he was a party before the courts."
Notley said she does not have an issue with Denis remaining as a candidate.
Alberta Agriculture Minister Verlyn Olson will take on the justice portfolio on a temporary basis.
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