Search teams will comb the second chamber of the cellar at Haut de la Garenne after a specialist sniffer dog gave a positive 'indication' yesterday.
First, forensics officers must remove building debris from the room slowly and carefully to avoid losing potential clues. The process is expected to last several days.
The specialist sniffer dog, which is trained to search for blood and human remains, has given no further positive reactions since being sent down into the room yesterday afternoon, and Jersey Police have warned against drawing premature conclusions.
Detectives entered the second of four underground rooms at the former care home, which is now a youth hostel, from above.
The second room is three times the size of the first, where police found blood specks in a shallow concrete bath last week. The first room also housed an item, believed to be shackles, and a secret trapdoor entrance.
On a wooden beam near the bath were scrawled the words: 'I've been bad for years and years.' Elsewhere on the site, police have found a child's skull and other bone fragments which may be human.
More than 100 people claim to have been abused at the home during the 1970s and 1980s.
Several hundred people held a rally on Saturday to protest against what they claim is a 'culture of secrecy' on the island.
