Cancona Police had yesterday registered an FIR against builder Vishwas Desai and contractor Jaideep Saigal for allegedly endangering human life, causing death and negligence following the collapse.
"Both the builder and contractor have been missing while attempts are on to trace them," police inspector Harish Madkaikar told PTI.
Thirteen people were killed when an under-construction five-storey residential building caved in Cancona town, about 70 kms from here, yesterday.
Over 20 people could still be under the rubble of the building but the possibility of finding more survivors at the site appears bleak as a huge pile of debris is affecting the pace of rescue operations, fire personnel said.
More From This Section
But, the priority right now is to rescue people from the debris, he said.
Personnel of Goa fire and emergency services and Army carried out rescue operations overnight to look for more survivors.
Officials said the building was being developed by Navi Mumbai-based Bharat Realtors and Developers.