Follow-up police searches have failed to find any trace of two fishermen drowned at Lake Tekapo or a Malaysian tourist missing at Mt Cook.
Alexander Haywood, 72, his son Antony, aged 46, and friend Murray Green, 54, of Timaru, lost their lives on a fishing trip on Lake Tekapo on October 21.
Police believe the men were thrown overboard when their boat hit a submerged object.
Alexander Haywood's body was found floating just below the surface within hours of the accident, but extensive police and private searches at the time failed to find the other two bodies.
A search and rescue team returned to the lake last weekend for a final search, but did not turn up any clues, Senior Constable Les Andrew told NZPA.
Bodies that sank deep in the lake usually never returned to the surface because of the cold temperature of the water, he said.
"I think there's still seven bodies in there from over the years."
A final search has also failed to find Malaysian tourist Kok Wong, aged 33, who left the Mt Cook Youth Hostel on September 30 for a day walk near The Hermitage but never returned.
He left no record of which track he planned to take, making the initial search difficult.
A seven-hour follow-up search using a cadaver dog had since been undertaken without success, Mr Andrew said.
However, he was optimistic Mr Wong's body would eventually be found.
"He can't be far away because he was not equipped for a bigger tramp."
Both matters will now be referred to the coroner.
