Nuns claim they are ''being forced to violate'' their vows by selling their convent to Katy Perry.

The 'I Kissed A Girl' hitmaker has become the source of a dispute after she bought a hilltop property from the Archbishop of Los Angeles for $14.5 million last year, with the nuns who last lived in the building claiming they had the right to sell it and do not want the 30-year-old singer to occupy their former home.

In an email correspondence sent from Sister Catherine Rose Holzman to Archbishop Jose 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.''

In other documents submitted by Sister Catherine Rose, 86, and Sister Rita Callanan, 77, of the Sisters of the Most Holy and Immaculate Heart of the Blessed Virgin Mary, they accused the Archbishop of acting as if he were ''above the rules and immune from the obligations of civil law''.

Sister Jean-Marie Dunne, 88, has also accused church officials of ''not possessing a modicum of humility'' while dealing with the case.

The five sisters of the convent - aged between 77 and 88 - are instead believed to have organised their own sale on the Gothic property to local restaurateur Dana Hollister for $1 million more than the 'Roar' singer's offer, despite the fact the Archbishop claims the sale was not binding as the nuns are under his authority.

While two of the five nuns are believed to have signed statements supporting the sale to Katy, Sister Rita and Sister Catherine Rose claim one of them was on morphine at the time so was not fit to do so.

Katy - who released her fourth studio album 'Prism' in 2013 - previously tried to win over the nuns by singing to them and showing them a tattoo of the name ''Jesus'' she has written across her wrist, although they insisted they were unimpressed by the meeting.