The Flemish artist's first choice was Andrea Mantegna's "Mother and Child", but the painting wasn't on the list of available works from the Accademia Carrara in Bergamo. Her next choice was Antonello da Messina's "Crucifixion" from the Royal Museum of Fine Arts in Antwerp, but it turned out that wasn't available either.

It was time for a meeting with the exhibition's curator, Giovanni Carlo Federico Villa. De Bruyckere, 45, recalls Villa visiting her studio in Ghent and talking about the beauty and iconography in Giovanni Bellini's "Mother and Child". De Bruyckere (pictured below) fell for the painting and realised it would work well with her own work "Pieta". Once that selection was made, De Bruyckere was keen to stick with the same artist for a second pairing. She chose Bellini's "Pieta: Dead Christ Supported by the Madonna and St John", juxtaposing it with her own "Lingam".

When you see Bellini's and De Bruyckere's works facing each other, it is actually the contrasts that are immediately striking: 15th-century paintings of sacred subjects opposite 21st-century wax sculptures of mutilated bodies. "Some people will be shocked, but it is not a provocation," says Bozar director Paul Dujardin.

Bellini's "Mother and Child" shows the Virgin Mary, with downcast eyes, holding a baby Jesus resting on a tomb-like surface and trying to escape from her arms. Mary's blue cloak with gold thread and the red of the marble are rich and beautiful, and the playful child is a person full of life. But Mary's face, and the child's struggles presage the suffering and death of Jesus.

Opposite, De Bruyckere's "Pieta" is also a work of two parts - an emaciated, mutilated male body lying on a bed of soft, white cushions. "The cushions are like a person taking care of a body," De Bruyckere tells me. For her, the term pietà - Italian for "pity" and used to describe works that depict Mary with Christ's dead body - means much more than religious iconography.

"In war, when two soldiers take care of each other, this is also a form of pietà," she says. "It's two bodies taking care of each other, not just the Virgin and Christ." In this case, the second body takes on an abstract form in the shape of the cushions. The work evokes not only death, but also the fragility of life.

Bellini's "Pieta", meanwhile, depicts the dead Christ flanked by the Virgin Mary and St John the Evangelist. At the base of the painting is a wooden plank, on which Bellini has engraved his name, in his traditional signature style, and which acts like a frame keeping the three figures trapped in the picture.

The equivalent in De Bruyckere's "Lingam" is the wooden chapel niche in which she has suspended a deformed and headless wax body. The tears of Mary and St John in Bellini's work contrast with the lack of facial expression in De Bruyckere's where the twisted body alone tells the story of horror, injustice and death. Yet both portray wounded flesh and suffering.

Both of De Bruyckere's sculptures are made from her usual medium of wax and in her familiar palette of white and cream, with gentle hues of pink and blue. "I feel very much like a painter when I start," she explains. "You see the surface, the different layers of wax on top of each other, like a painting."

The technicalities of working with wax are complicated, from making the moulds of bodies to knowing how hot each layer needs to be. This determines how deep they will melt and, therefore, what effect will be created.

De Bruyckere has been a name on the international scene for several years now, with her big break coming at the 2003 Venice Biennale, when her sculptures were shown in the Italian Pavilion. She was part of the major exhibition of Flemish artists in Singapore in 2009 and last year won the Flemish Culture Prize in visual arts.

She produces 10 to 15 works a year - the number depends on the size of the sculpture, with "Pieta" taking several months and "Lingam" several years. Admittedly, the delay with "Lingam" was largely to do with the difficulty in stripping down the 17th-century chapel niche, removing its beautiful features and reducing it to its essential form - a process that, incidentally, the artist doesn't feel guilty about.

De Bruyckere's interventions in the Venetian and Flemish Masters exhibition were the result of several years of talks. Originally, De Bruyckere was to confront the old masters in a solo exhibition planned at Bozar for 2012. But the artist was concerned that too many galleries were pursuing this type of show.

So now the idea for 2012 is to place De Bruyckere's work in confrontation with contemporary artists, the seed of which has now been planted. The current interventions act like an introduction to next year, she says, a hint that "a huge exhibition is coming."