The latest body parts have been recovered from a water purification centre in Wevelgem.
Earlier body parts were found in a stream in the village of Moorsele. The find included a woman's head that had been wrapped in a plastic bag.
News of the new discovery has been confirmed by the Kortrijk public prosecutor's office. The 42-year-old woman went missing in February when she was walking her dog. Her boyfriend was detained and first made a confession, but later retracted. His lawyer said that he had been pressurised by the police.
The woman's younger boyfriend had to be released due to lack of evidence.