A brief Vatican statement said Pope Francis had "accepted" the resignation of Msgr. Dario Vigano.

It comes after the Vatican admitted blurring part of a letter about Pope Francis written by his predecessor, in a picture sent to the media.

The tampering caused controversy amid concern over so-called "fake news".

Professional standards of photojournalism forbid adding or removing anything from photographs, especially manipulations that alter their meaning. Media outlets covering the Pope often rely on handout images from the Vatican.

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The row began after Msgr. Vigano, whose official title was prefect of the Vatican Secretariat for Communication, asked Pope Benedict XVI to write some "dense theology" to be read at a presentation event for a new series of books about Pope Francis.

In his letter, Pope Benedict welcomed the publication of the volumes, but said he would not be able to write a reflection because he would not have time to read them.

Msgr. Vigano read selected passages from the letter at a presentation on 12 March. Then journalists received a doctored image of the letter, which blurred out the lines where Pope Benedict explained he would not be reading the books.

In his letter of resignation (in Italian), Msgr. Vigano told Pope Francis that although it was not intentional, his actions had "destabilised the complex and great work of reform".

"I think that for me stepping aside would be a fruitful occasion for renewal," he said.

The Vatican press office has not explained why the picture of the letter was doctored. It told the Associated Press that it was never intended for full publication.

 The Vatican said it had not planned to publish the letter in full

Though Pope Benedict is often characterised as a more hardline, doctrinaire pontiff than Francis, he has spoken warmly of his successor and his "goodness".

For his part, Francis has praised Benedict's decision to resign from the papacy in 2013 as "courageous".

"I think that a Pope emeritus should not be an exception," he told reporters in August 2014. "You can ask me: 'What if one day you don't feel prepared to go on?' I would do the same, I would do the same!"