The intruder had failed to account for one brave sister who stopped the assailant and raised the alarm before the thief could escape with the money.

The incident took place at the Convent of Saint Clare in Palencia in northern Spain on Monday.

The unnamed 87-year-old nun became suspicious when she saw a woman in her forties going into one of the rooms. She reportedly saw her try to steal an envelope containing money collected for people in need. A scuffle ensued. Another sister, upon hearing the commotion, ran into the room only to find the nun on the ground with the suspect.

She lifted the elderly sister and prevented the alleged thief from fleeing.

“I took the sister out of the room and then locked the door, leaving the woman who had entered the convent to steal inside,” she added.

Sister María Beatriz told radio broadcaster Onda Cero that the woman, who was known to the convent, had “waited for her opportunity”.

Police arrived and arrested the suspect.