They received the alert at 4am on Saturday and used air, Coastguard and fire and rescue services to search the River Tay.
RNLI lifeboats from Broughty Ferry and the Coastguard search and rescue helicopter from Prestwick were initially involved in the search.
Police said they were continuing the search using divers and specialist search units.
Chief Inspector Maggie Pettigrew said: “We carried out extensive multi-agency searches over the weekend and today our dive and marine unit will be carrying out searches near to Moncrieffe Island.
“Our air support and operational support units will carry out further air and land searches.
“If you have any information that could assist us, please contact 101 or speak to any police officer.”