Pope Francis on Thursday sacked a Paraguayan bishop who had been accused of protecting a suspected paedophile priest.

In an official statement, the Vatican said the removal of Ciudad del Este bishop Rogelio Livieres Plano had been a "painful decision taken for serious pastoral reasons."

The decision to fire the conservative bishop follows a visit to Paraguay by a Vatican delegatation charged with investigating a case that had led to a public war-of-words between the South American country's senior clerics.

Livieres had been publicly attacked by his colleagues in Paraguay for promoting and defending an Argentinian priest who has been accused of sexual abuse.

"This grave decision of the Holy See was taken for serious pastoral reasons and was motivated by the greater good of unity in the church of Ciudad del Este and the episcopal communion in Paraguay," the Vatican statement said.

The Argentinian priest, Carlos Urrotigoity, had been named Livieres's number two in the diocese, despite having been been accused of molesting minors while he was serving in a parish in Pennsylvania, in the United States.

The American diocese where he worked has publicly described him as "a serious threat to young people."