UPDATED 3.09PM: GNS scientists are investigating whether White Island has thrown out any volcanic material or ash after last night's eruption.

A small eruption occurred on the island sometime between 9.30 and 11 o'clock last night.

As a consequence, the Volcanic Level Alert has been raised to level three, and aviation colour code to orange.

The eruption was accompanied by moderately elevated seismic activity, which is now back to normal.

It deposited material over the north side of the crater floor, and up onto the crater wall.

Volcanologist Nico Fournier said they will be conducting investigations from the air today, to gather more information on how far the material and ash travelled.

"Since 11 o'clock last night, activity has been very quiet on islands, but of course we always are concerned that the volcano is in a little bit more unrest at the moment."

He said the team is keeping a close eye on the volcano.

"We will be flying around the island to gather more information to know a bit more about the distance of the material that was ejected, how far it went and also determining whether or not any blocks have been ejected in addition to ash."