Researchers in north Queensland of Australia on Monday said they may have discovered a tiny new species of seahorse.

Scientists from James Cook University (JCU) have just returned from a week-long expedition about 200 kilometers off Cairns of state Queensland.

According to Expedition leader Tom Bridge, the project aims at examining what lives deep beneath the ocean, and scientists were looking at corals and the creatures that live in the "twilight zone" - an area between 30 and 150 meters below the ocean's surface.

"As you go deeper and deeper you find less familiar critters," Bridge told ABC News on Monday.

"We found a tiny little seahorse that was about four or five millimeters tall.

"Pygmy seahorses have been discovered, before but I've never seen one quite that small before and no one has ever recovered one from quite that deep either."

He said scientists took samples of the tiny seahorses back to the university to study, where they will look at the skeletons, and examine of exactly what they are.

It will be a fairly long process, especially if it is not something that has been described before, Bridge said.