The former pope Benedict has claimed that his resignation in February was prompted by God, who told him to do it during a "mystical experience".

Breaking his silence for the first time since he became the first pope to step down in 600 years, the 86-year-old reportedly said: "God told me to" when asked what had pushed him to retire to a secluded residence in the Vatican gardens.

Benedict denied he had been visited by an apparition or had heard God's voice, but said he had undergone a "mystical experience" during which God had inspired in him an "absolute desire" to dedicate his life to prayer rather than push on as pope.

The German ex-pontiff's comments, which are said to have been made a few weeks ago, were reported by the Catholic news agency Zenit, which did not name the person Benedict had spoken to.

A senior Vatican source said the report was reliable. "The report seems credible. It accurately explains the spiritual process that brought Benedict to resign," he said.