A music festival in Poland that was due to take place in the city of Krakow from yesterday until next Sunday has seen several of its concerts cancelled after allegations that it promotes devil-worshipping.

Several gigs at the electronica-oriented Unsound Festival were due to take place at St. Catherine's Church and The Church of St. Peter and Paul, but after a letter was sent to both churches alleging that the festival's organisers promoted Satanism, they refused to allow the gigs to take place.

It is not known who sent the letter, but the artists that were due to perform in the venues included pianist John Tilbury, Polish jazz guitarist Raphael Roginski and American musician Rrose, as well as Current 93, aka British experimental musician David Tibet, who they say has discussed his Christian faith in past interviews. Tibet also had a 1994 song called 'Lucifer Over London', which may give some indication - albeit tenuous - of where the allegations stem from.

The organisers released a statement describing the Satanism accusations as 'preposterous' and 'unfounded, unreasonable and slanderous'. 

"They undermine the good name of the festival, which since 2003 has been an enthusiastic participant in Krakow's cultural life, and we reject the accusation unequivocally," it read.

"Were it possible to ignore this as a sick joke, we would. Unfortunately, this statement harms not only the festival organisers, but also our guests – including both artists and the festival audience.

"As the organisers of Unsound, we of course categorically deny that Satanism is now or has ever been promoted at our festival. The goal of the Unsound festival has always been bringing artists and audiences together in the promotion of art and culture. "