The 59-year-old Christchurch man was reported overdue about noon on Saturday, having been expected to return a couple of hours earlier from his trip on Canterbury's Lake Ellesmere.
On Monday, Detective Brent Menzies said while no one was with the man at the time of the incident, police believed he had come out of his kayak, which was then pushed away by the prevailing wind.
READ MORE: * Kayaker reported missing on Lake Ellesmere * Kayaker reported missing on Lake Ellesmere still not found
"Unfortunately, due to the amount of time that has passed, we are now searching for a body," Menzies said.
"While no formal searches were conducted today, we expect to undertake further aerial and water-based searches of the lake tomorrow.
4 Person Kayak Sale
"There have been a number of drowning-related deaths over the holiday period, and police would like to remind everyone to be conscious of their safety and wear lifejackets when conducting any activities on the water."
A helicopter, jet skis and inflatable rescue boats were brought in to look for the man, but did not find any sign of him.
Single Kayak, Children Kayak, Electric Trolling Motor, Kayak Parts - Oceanus,https://www.blueoceankayak.com/