The Archbishop of Canterbury, Justin Welby, has resigned following criticism of his handling of a report into a prolific child abuser associated with Church of England.

Mr Welby apologised last week after the report described a barrister who ran summer camps for young Christians, John Smyth, as the most prolific serial abuser associated with the Church.

Mr Welby said he had "no idea or suspicion" of the allegations before 2013, but the independent report concluded that it was unlikely he would have had no knowledge of the concerns regarding Mr Smyth in the 1980s.

"Having sought the gracious permission of His Majesty The King, I have decided to resign as Archbishop of Canterbury," Mr Welby said in a statement.

"I hope this decision makes clear how seriously the Church of England understands the need for change and our profound commitment to creating a safer church. 

As I step down I do so in sorrow with all victims and survivors of abuse."

In his role as the Archbishop of Canterbury, he was the spiritual leader of 85 million Anglicans worldwide.

Mr Welby had been under significant pressure to resign, but had ruled out stepping down as recently as last week.

The independent report had found that Mr Smyth had subjected more than 100 boys and young men to "brutal and horrific" physical and sexual abuse over a 40-year period, according to Reuters.

Mr Smyth was chair of the Iwerne Trust, which funded the Christian camps in Dorset in England, and Welby worked at them as a dormitory officer before he was ordained.