Poland's supreme court has issued a landmark judgment against a heavy metal musician who tore up a Bible at a gig in 2007. Although the judges conceded that Adam Darski, AKA Nergal, did not intend to offend his audience, they ruled that he could still have "offended religious feelings", violating Polish law. If found guilty, the singer could face up to two years in prison.

Darski had released eight albums with his band, Behemoth, by the time of their notorious performance in Gdynia on 13 September 2007. Appearing in full costume and makeup, Darski tore up a Bible and described the Catholic church as "the most murderous cult on the planet".

"We'd been doing that for two years on tour before it happened in Poland," Behemoth bassist Tomasz Wróblewski told Decibel magazine (via Blabbermouth). "We [were] not offending any particular person. We [were] just offending the religion that we've been raised in."

Despite this intention, Darski was pursued by Polish courts for having offended Catholic fans. After being cleared by judges in 2010 and 2011, the singer/guitarist is again on trial. Officials in Gdansk asked the supreme court how Darski could be "offending religious feelings" if most of Behemoth's fans expected theatrical sacrilege?

"The crime of offending religious sensibilities is committed not only by he who intends to carry it out, but also by he who is aware that his actions may lead to offence being taken," the court said. Prosecutors have been permitted to pursue with the criminal trial.

"One should respect the court's verdict," Darski told journalists. But the Catholic church is also "immature", he said, "trying to gag people … [and] freedom of speech". Speaking to Reuters, Darski's lawyer said they would continue to oppose the charges: "We are still arguing that we were dealing with art, which allows more critical and radical statements," Jacek Potulski explained.

Darski is currently a judge on the TV singing competition The Voice of Poland. Behemoth's most recent LP, Evangelion, was released in 2009. It reached No 2 in Poland.

• This article was amended on 2 November 2012. The original photograph was of Tomasz Wróblewski. This has been corrected.