The head of a Spanish children’s charity has been arrested on suspicion of child abduction after allegedly kidnapping her own 11-year-old son and holding him captive, along with another child.

María Sevilla, 36, who advised Left-wing party Podemos in her capacity as chairman of ‘Free Childhood’, an organisation seeking protection for child abuse victims, is understood to have kept her son and six-year-old daughter locked up at a rural property near Cuenca, central Spain, since September last year.

The two children were found hidden in “deplorable” conditions, police sources told local press.

Ms Sevilla had taken extreme security measures, and they were only allowed outside for 20 minutes a day, once it was dark, supervised by the girl’s father.

Spain’s national police confirmed that Ms Sevilla was in breach of an order granting full custody of her son (only referred to as Baby S) to his father, Rafael Marcos.

“He is like a broken child, afraid of everything,” Mr Marcos told Spanish TV on Tuesday. “When he first saw me, he looked paralysed with shock.”

“I know that he got up at lunchtime, practically in the afternoon, then spent the rest of the day watching soaps with his mother, and little else,” he added. “It was as if he was in prison.”