A judge is set to make a decision about whether Katy Perry is allowed to buy a convent.

The Sisters of the Immaculate Heart of Mary insist they have the right to sell the property, which boasts birds'-eye views of LA, to Dana Hollister for $15.5 million, but the Los Angeles Archdiocese claims the nuns' sale is not authorised.

The archdiocese claims its agreement to sell the convent to the 31-year-old singer for $14.5 million is legally binding.

According to The Los Angeles Times, the judge is expected to make a decision on two motions in the next 60 days.

The 'Firework' hitmaker and the church claim the nuns didn't get approval for the sale form Archbishop Jose Gomez, while Michael Hennigan, who represents the archdiocese, insists Gomez controls the institute rather than the sisters.

Katy's company Bird's Nest has also asked for the sole right to buy the building.

But a lawyer for two of nuns, John Scholnick, hit back at the two motions, saying more evidence should be gathered before the judge makes a decision.

Last July, the nuns claimed they were "being forced to violate" their vows by selling their convent to Katy.

In an email correspondence sent from Sister Catherine Rose Holzman to Archbishop Gomez from May 22, she wrote: "In selling to Katy Perry, we feel we are being forced to violate our canonical vows to the Catholic Church."