LONDON (Reuters) - Justin Welby, the former spiritual leader of Anglicans worldwide, reiterated he had failed to ensure proper investigations into allegations of abuse within the Church of England, saying the scale of the issue was "overwhelming".

Welby stepped down as Archbishop of Canterbury in November 2024, after calls for him to resign intensified following a report that found he had taken insufficient action to stop one of the Church's most prolific serial abusers.

The report said John Smyth, a British lawyer who volunteered at Christian summer camps, had subjected more than 100 boys and young men to "brutal and horrific" physical and sexual abuse over a 40-year period.

In an interview with the BBC, which will be broadcast in full on Sunday, Welby said "every day more cases were coming across the desk that ... hadn't been dealt with adequately (in the past)".

"This was just, it was another case - and yes I knew Smyth but it was an absolutely overwhelming few weeks," Welby said. "It was overwhelming, one was trying to prioritise - but I think it's easy to sound defensive over this."

"The reality is I got it wrong. As Archbishop (of Canterbury), there are no excuses," he added.

The Church of England did not immediately reply to a request for comment on Welby's interview.

Smyth moved to Africa in 1984 and continued to carry out the abuse until close to his death in 2018, the report said.

The report found the Church of England had known at the highest level about the sexual abuse claims in 2013 and Welby became aware, at the latest, about the accusations in the same year, after he became Archbishop of Canterbury.

Media reports since Welby resigned have alleged more abuse within the institution.

(Reporting by Catarina Demony; Editing by Aidan Lewis)