A Spanish archbishop has been summoned to the Vatican to explain perceived failings in his investigation of a group of priests accused of being paedophiles.

It's after a young man who claimed to have suffered brutal sexual abuse wrote to Pope Francis appealing for help.

It's reported the pontiff called the 24 year old alleged victim to ask him to 'forgive this extremely serious sin'.

Vatican officials then contacted the archbishop of Granada, Francisco Martínez, ordering him to carry out a full investigation and take appropriate action.

Reports say the archbishop removed the accused priests from their roles but it's alleged he did not punish people who tried to cover up the accusations.

He's defended his investigation and actions saying he acted promptly and that evidence was needed before further action could be taken.

Newspapers say Pope Francis has again telephoned the victim to express his regret at the limited scope of the investigation.

It's expected the Holy Father will ask Archbishop Francisco Martínez for an explanation at a face to face meeting this weekend.