A sex abuse investigator for the Roman Catholic Church in England has been convicted of Internet paedophile offences, it emerged Thursday night.

Chris Jarvis, the former child safeguarding officer for the Diocese of Plymouth, will be sentenced Friday for possessing more than 4,000 images of children being abused, including some in the most serious category, The Times have reported.

Jarvis will appear at Plymouth Crown Court having pleaded guilty to 11 charges of making and possessing indecent images of children.

Ten of the photos were classified as the most extreme category of abuse, which is defined in law as involving sadistic violence. There is no evidence that he was directly involved in the abuse of the children in the photographs.

Jarvis was caught after uploading five of the images onto a social network site, which alerted the police. A further search of his home revealed thousand more images, with many more stored on his laptop.

The Roman Catholic Church will now order a wholesale review of child protection across the South West of England.

Earlier his week, the Vatican ordered an inquiry into abuse at Ealing Abbey in West London. There are now likely to be calls for that inquiry to be extended to a national review.

The main focus of the inquiry was St Benedict's School after a recent investigation exposed four decades of abuse at the school. This resulted in the arrest of Father David Pearce, the former head of St Benedict's, who admitted carrying out assauts between 1972 and 2007.

These latest revelations that the church employed a paedophile in a child protection role will add to the increasing sense of crisis of its handling of cases of clerical sexual abuse.

At the time of his arrest, Jarvis was leading an investigation into sex abuse allegations at Buckfast Abbey, another Benedictine monastery, in Devon. He was responsible for child protection at 120 churches and parish community groups for nine years.

Earlier this month police revealed they were hunting a Catholic cleric over allegations of child abuse dating from when he taught at St Benedict's.

Father Laurence Soper, 80, did not answer bail last week and is now though to be in a monastery in Rome.