A faceless fish and toxic urchins are just some of the undiscovered creatures that have been found deep beneath the Australian ocean during an expedition of the uncharted eastern abyss.

"We haven't found any sea monsters yet but we are still looking and keeping our eyes out," chief scientist of the Sampling the Abyss Expedition, Dr Tim O’Hara said.

Dr O’Hara told nine.com.au he is halfway through a month-long exploratory journey of the massive abyss - which covers more than half the world's oceans - while describing the list of deep-sea creatures he and his team from the Museums Victoria have discovered four kilometres below the surface of the ocean.

A species of faceless fish is among his team's most recent findings.

"We have found everything from starfish to faceless fish which really looks quite alien. Everything down there at the crushing depth lives in practically no light and freezing cold water and many of the creatures have big fangs and no eyes and use smell to catch their prey," Dr O'Hara said.

"We have found fish with what looks like camera tripods under their mouths so they can sit on the sea floor and poisonous sea urchins with spines that look like flat pancakes. We use gloves and eye protection when we handle most of the species just in case."

The Australian scientist said he had also observed a vast array of species that glow through bioluminescence as a defence mechanism to scare away predators.

O'Hara and his team are on board an Australian Government research vessel on loan from the Commonwealth Scientific and Industrial Research Organisation (CSIRO) on a mission to better understand Australia’s deep-sea habitats and biodiversity.

"It's an experience being out here. We have found thousands of specimens so far and I would say at least one-third of them have never been seen before," he said.