Two crews staged a major search and rescue operation overnight on Sunday only to discover that the distress flare they were responding to was actually a harmless paper lantern.

The Coastguard revealed that this was the fourth such incident in the space of just seven days -- and that a previous call-out involved a helicopter hired at a cost of £6000 an hour.

The festive lanterns are like small hot air balloons, made of paper stretched round a light bamboo frame with a flame inside to send the glowing globe soaring into the sky. Many people set them off into the night sky at parties or barbecues.

A Coastguard spokesman told the Evening Times: “It’s happening more and more, it seems to be catching on here.

“A lot of time and effort is involved, and there’s only a finite amount of money. A helicopter costs about £6,000 an hour -- it’s taxpayers that are paying for that.”

Last night’s rescue mission was sparked by sightings of what appeared to be a red distress flare between Dunoon and Gourock.

The lanterns appear very similar to maritime distress flares, as both glow with a reddish light and hover in the air.

Coastguard teams have to treat every call-out as a real emergency, and a false alarm like last night ties up crews so that they can’t respond to real accidents elsewhere.