Madonna has gone ahead with a concert in Dusseldorf despite warnings that German prosecutors were considering legal action over the show's content.
The cross use has been criticised in most countries on the tour
Prosecutors said they were to monitor the performance after receiving a complaint that the US pop star's act breached German laws against blasphemy.
In one scene Madonna is seen in a mock crucifixion, wearing a crown of thorns.
A German Lutheran bishop has called for concert-goers to boycott all dates on the German leg of Madonna's tour.
Madonna says the performance is part of an appeal for Aids charities.
The segment where she appears on a cross has provoked controversy in several countries and been criticised by the Vatican and Russian Orthodox Church.
But the German prosecutors admitted they would rely on media reports of the concert rather than send their own observers to decide whether further action should be taken.
Protestant Bishop Margot Kaesmann told German newspaper Bild am Sonntag that concert-goers should boycott the show.
"I thought Madonna was better than this because she claims to be a religious person," she said. "But maybe the only way an aging superstar can attract attention is to offend people's religious sentiments."
"I advise people to ignore Madonna. Stars come and go, but the Christian faith endures," Bishop Kaesmann added.
Madonna's New York-based spokeswoman, Liz Rosenberg, denied that the star's show was insulting.
"The context of Madonna's performance on the crucifix is not negative nor disrespectful toward the church," she said.