“Since the vehicle Jeremy was using arrived at the carpark, there has been no activity on his bank accounts or mobile phone,” How said.

“Given these facts, police believe the most likely scenario is that he died shortly after arriving in the Green and Blue Lakes area.”

How said neither Robertson nor any suspected belongings were found during yesterday’s search.

Search efforts included using a drone to search around the lake and nearby islands.

“Police remain committed to locating Jeremy if at all possible, to provide the closure that Karen’s loved ones deserve,” How said.

“Further smaller-scale searches are going to be undertaken in the future.”

An aerial view of Lake Tikitapu (Blue Lake). Photo / NZME

How said police urged the public to contact them with any information.

“We’d like to hear from anyone who has previously located any medication packets, or any red or blue clothing in the area surrounding the lakes, and nearby tracks.”

Police can be contacted via 105, either over the phone or online at 105.police.govt.nz.