Forensic work in the dungeon where an Austrian man allegedly held his daughter for 24 years is "oppressive", police chief Franz Polzer has said.
Officers wearing special masks can only work one hour at a time because of the lack of oxygen in the windowless cellar, he told AP news agency.
Police say Josef Fritzl, 73, imprisoned and raped his daughter Elisabeth in the cellar in Amstetten in Lower Austria.
They say she bore his seven children - three of whom never saw daylight.
Mr Fritzl, who is in custody, has confessed to the crime in a written statement, police say.
Mr Fritzl is refusing to answer any more questions, as police try to piece together conditions in the cellar - as well as the suspect's life.
Austria cellar probe 'oppressive'v
Forensic work in the dungeon where an Austrian man allegedly held his daughter for 24 years is "oppressive", police chief Franz Polzer has said.
Officers wearing special masks can only work one hour at a time because of the lack of oxygen in the windowless cellar, he told AP news agency.
Police say Josef Fritzl, 73, imprisoned and raped his daughter Elisabeth in the cellar in Amstetten in Lower Austria.
They say she bore his seven children - three of whom never saw daylight.
Mr Fritzl, who is in custody, has confessed to the crime in a written statement, police say.
Mr Fritzl is refusing to answer any more questions, as police try to piece together conditions in the cellar - as well as the suspect's life.
