Searchers have so far failed to find any sign of whoever, or whatever, appeared to activate a flare off the coast south of Oamaru this evening.
The search is being scaled back and an appeal for those at sea to keep a lookout for vessels in distress has been cancelled.
"We have been unable to find a boat or anyone in distress in the water,'' a police spokeswoman said shortly before 8pm.
Police and the Rescue Co-ordination Centre were advised after a red flare was seen off the coast between All Day Bay, just south of Kakanui, and Moeraki.
Nor were cars and trailers found at any boat ramps from Oamaru to Moeraki.
A police spokeswoman said earlier the red flare was reported about 6pm off the coast between All Day Bay, just south of Kakanui, and Moeraki.
Police had been advised and an officer was heading to the area, she said.
A call came over Maritime Radio Channel 16 at 6.42pm to advise the Rescue Co-ordination Centre was asking vessels in the area for further information about the activation of the flare.
Another appeal to keep a close eye out for any stricken vessels and assist if necessary came over the same channel an hour later.
At 8.20pm, a message came over cancelling the call for sightings.
