The dungeon in Austria where Josef Fritzl kept his daughter Elisabeth as a sex slave for 24 years and fathered seven children with her is now being filled with concrete.
Preparation work for the process started in Amstetten on Thursday and will last for about two weeks, the BBC reported.
The man, who was appointed to liquidate Fritzl's estate, said that the step had been so that no-one could enter the cellar ever again.
78-year-old Fritzl was jailed for life in March 2009 after being convicted of murdering one of his children through neglect, as well as rape, incest, and enslaving his daughter.
The authorities were believed to be concerned that the dungeon could become a gruesome tourist attraction.
