Pope Benedict XVI personally intervened this summer in a row over a controversial sculpture of a crucified frog at a museum in Bolzano in northern Italy while he was on holiday nearby, a local politician has disclosed.

Franz Pahl, president of the Alto Adige regional council - who at one stage went on hunger strike in a bid to have the sculpture by Martin Kippenberger removed - said the Pope had written to him earlier this month to condemn the work, saying it had "injured the religious feeling of many people who see in the cross the symbol of the love of God and of our salvation which deserves recognition and religious devotion."

Pope Benedict was on holiday at the time at a seminary in Bressanone, a town near Bolzano, and is known to have discussed the work with Monsignor Wilhelm Egger, the local bishop. However Monsignor Egger, who has since died, declined to say what the pontiff thought about the sculpture.

The sculpture went on show at the Museum of Modern and Contemporary Art in Bolzano in May. After a chrous of protests from local Catholics the organisers moved the offending sculpture from the entrance to an upper floor, but refused to remove it altogether.

Museum curators maintain that the work is not anti religious but rather a "self-portrait of the artist in a state of profound crisis". The museum director Corinne Diserens said 26,000 people had visited the frog so far, and Kippenberger's work would remain in place until the exhibition ends on 21 September.

Earlier this month (August) the Union for South Tyrol, a separatist group, said it had collected 10,000 signatures for a petition demanding the removal of the crucified frog. Luis Durnwalder, the head of the local province, said he supported contemporary art, but not "pure provocation ... The principles of respect for popular feeling and of artistic freedom have to find a reciprocal tolerance through good will and with understanding from both sides."

Two years ago the Bolzano museum hit the headlines by displaying a work of art consisting of a toilet flushing to the accompaniment of Italy's national anthem.