Is that confirmed?
"At about 23.00 accompanied by a PJ inspector, the searches were begun. After Rex was given the girl's clothing to sniff, he began to search on the ground floor of block 5 and when he passed the door of apartment 5 A (the place the girl had disappeared from) according to his handler, officer Fernandes, the dog altered its behaviour, sniffing with greater intensity than he had done before. Apartment 5J of the same block was also checked as the dog had been more agitated than before as if there were a very strong strange odour there. It was stated that this apartment had been unoccupied for some time. Afterwards, the same kind of search was carried out using the dog Zarus which in general terms showed the same behaviour in the same places as Rex had done."
Documented Evidence - Page 5