* Francis's move highly unusual for a bishop
* Pope wants austere Church with transparent finances
* Future of high-spending bishop unclear
Pope Francis on Wednesday banished a German Roman Catholic prelate known as the "luxury bishop" for spending 31 million euros ($42.70 million) of Church funds on his residence at a time when the pontiff is stressing austerity.
In a highly unusual move, Bishop Franz-Peter Tebartz-van Elst of Limburg was ordered to leave his diocese while an investigation and audit into cost over-runs is held.
A Vatican statement said the bishop, who met the pope on Monday to discuss the scandal in the German Church, "was currently not in a position to carry out his episcopal ministry". It said he should stay outside his diocese "for a period," and that it would be administered in his absence by a vicar-general.
The issue has proven a major embarrassment for the pope, who has called for a more austere Church that sides with the poor and has told bishops not to live "like princes".
Francis has also promised to clean up the murky finances of the Vatican's own bank and has set up a commission to advise him on whether it should be restructured or even closed.
The German media has dubbed Tebartz-van Elst "the luxury bishop" after an initial audit of his spending, ordered after a Vatican monitor visited Limburg last month, revealed the project cost at least 31 million euros - six times more than planned.
Tebartz-van Elst, whose baroque style has appeared more in line with the conservative model of Roman Catholicism projected by retired German-born Pope Benedict, has also been accused by German magistrates of lying under oath about a first-class flight to visit poverty programmes in India.
German media, citing official documents, said the residence had been fitted with a free-standing bath that cost 15,000 euros, a conference table that cost 25,000 euros and a private chapel for 2.9 million euros.
The pope's decision on the fate of Tebartz-van Elst was unusual because it appeared to leave him in limbo, falling somewhere between a suspension and outright dismissal.
This was apparently to buy time for the Vatican and German Church leaders to review the situation in the troubled diocese along with its broader ramifications.
The "luxury bishop" story has been front-page news in Germany for weeks, deeply embarrassing a Church enjoying an upswing thanks to Pope Francis's popularity after years of criticism for hiding sexual abuse cases among clergy.
Tebartz-van Elst, 53, is 22 years away from official retirement age in the Church and his saga represents an extraordinary management quandary for the Vatican.
Even if he eventually steps down from the diocese of Limburg, he would retain the title and rank of bishop, meaning the Vatican would have to find another post for him somewhere.
Last week, while the Vatican and the German Church were in crisis mode over the Limburg case, Tebartz-van Elst was kept waiting for eight days in Rome before the pope received him.
Archbishop Robert Zollitsch, head of the German bishops' conference, who met the pope last week to discuss the Limburg scandal, had urged Tebartz-van Elst to examine his conscience over the crisis he caused in the German Church.
The scandal has also put pressure on German bishops for more financial transparency in the entire Church in their country, forcing them to scrap centuries of secrecy over the reporting the value of their private endowments.
Germany's church tax, collected by the state and handed over to the churches, raised 5.2 billion euros for the Catholics and 4.6 billion euros for Protestants in 2012, making them major economic actors at home and abroad.
According to some media reports in Germany, the Limburg scandal has prompted more Germans to decide to formally leave the Church.