The volunteer organisation Missing People entered the search on Tuesday after police had been unsuccessful in their search for the 27-year-old, who was in training to become a certified diver. He went under water on Christmas Eve with no life lines.
Scuba divers from Missing People, local rescue services and a diving club in nearby Helsingborg have offered to help.
"Diving under ice is a special procedure and we have to be very careful in terms of security," county police officer Hans Nilsson told the news agency TT.
Missing People is a network of volunteers that has conducted several successful searches for people who have gone missing this year.