A figure of Adolf Hitler praying on his knees has caused controversy after going on display in the Warsaw ghetto.

The installation by Italian artist Maurizio Cattelan, titled "Him", has been placed in a district of the Polish capital which was the scene of the worst atrocities of the Nazi regime during World War II.

The Hitler statue is visible from a hole in a wooden gate and viewers can only see the back of the small figure praying in a courtyard.

Only those who have seen frontal photos of the figure on the Internet could recognize the unmistakable but rather youthful-looking face of the German dictator with his trademark moustache gazing upwards.

Poland's chief rabbi, Michael Schudrich, said the location of the installment offended the sensibilities of some people.

"I wouldn't say that it tarnishes the memory (of the Holocaust), because the memory is there, no matter what the art is. But I would say that the placing of the statue is so provocative not on the moral level, but just on the sensibility level, that it begins to be on the other side of appropriate and it really was an inappropriate place to where to place it," Schudrich told Reuters.

Cattelan is known for his provocative artworks, particularly a 1999 work showing Pope John Paul II being struck down by a meteor.