Katy Perry has taken a step closer to her dream home after a judge appeared to rule in her favour in a dispute with a group of elderly nuns over the sale of a $15m convent.

Los Angeles Superior Court Judge James Chalfant ruled on Thursday the order of nuns improperly sold the eight-acre estate near Hollywood to a businesswoman.

The ruling at first appeared to clear a path for the Los Angeles Archdiocese to sell the convent to Perry, but the judge put the brakes on that as well.

"There is no doubt in my mind sale to defendant (Dana) Hollister was improper and invalid," Judge Chalfant said.

He added, however, that church law governs the sale of the convent, not civil law, and it could take months, if not years, before the dispute was settled.

"You're not selling to Katy Perry anytime soon," he told the archbishop's lawyers.

The Sisters of the Immaculate Heart of Mary argue the hilltop property is theirs, and that they agreed to a $15.5m deal with local restaurateur, Dana Hollister.

The Los Angeles Archdiocese also claims rights to the property and wants to sell the estate to Perry after agreeing to a $14.5m deal.

Ms Hollister, who was already cleaning and restoring the convent, hoped to turn it into a boutique hotel and restaurant.

She stopped the project after she was sued by the archbishop.

The sisters have suggested they do not want to sell to Perry because of her suggestive songs and provocative attire.

"Well, I found Katy Perry and I found her videos … if it's all right to say, I wasn't happy with any of it," Sister Rita Callanan told the LA Times.

The Roar singer's bid to purchase the convent still requires Vatican approval.

Perry, who is the daughter of a pastor, was recently named as the highest earning female celebrity, making $135m last year.

Forbes' list showed she beat Taylor Swift who has hinted at "bad blood" with the fellow pop singer.

Perry, who has toured relentlessly over the last year, was the third highest-earning celebrity overall, behind boxers Floyd Mayweather Jr and Manny Pacquiao, who fought a highly anticipated match in May in Las Vegas.