An Air Force plane is on its way back to New Zealand after a fruitless search for a catamaran in distress near Samoa.

The search and rescue effort was sparked by an emergency locator beacon being set off - but rescuers now think someone probably thew their beacon away and it went off by mistake.

"We are confident there is no one in distress," a spokeswoman for Maritime NZ told the Herald.

The NZ Defence Force tweeted this morning that an Orion aircraft had left its Auckland base around 6am to look for a 30ft catamaran, after it set off a locator beacon near Apia, Samoa's capital.