Scientists have confirmed the presence of a deadly strain of bird flu on mainland Antarctica for the first time, posing a potential threat to the vast penguin colonies in the southern region.

"This discovery demonstrates for the first time that the Highly Pathogenic Avian Influenza virus has reached Antarctica despite the distance and natural barriers that separate it from other continents," Argentina's Higher Council for Scientific Investigation (CSIC) said on Sunday.

The presence of the virus was confirmed on Feb. 24 in samples of dead skua seabirds, which were found by Argentine scientists near the Antarctic base Primavera, CSIC added.

The confirmed case on the Antarctic peninsula, coming after cases on islands nearby, including among gentoo penguins, highlights the risk to colonies in the region to the H5N1 avian flu that has decimated bird populations around the world in recent months.

"Analysis has conclusively shown that the birds were infected with the H5 subtype of avian influenza and at least one of the dead birds contained the highly pathogenic avian influenza virus," CSIC said in a statement.

Hundreds of thousands of penguins gather in tightly packed colonies on the Antarctic continent and nearby islands, which could enable the deadly virus to spread quickly.

Data from the Scientific Committee on Antarctic Research also showed a now-confirmed case at the research base.