A Sydney cat nicknamed ‘Ozzie’ has become an international mystery after it was found living as a stray in Northern Ireland.

A microchip scan revealed the cat was registered in Sydney in 2000 and his birth year was recorded as 1989, indicating he is 26-years-old.

UK animal welfare group Armagh Cats Protection has received help from the Australasian Animal Register to contact the original owner but they have had no successful attempts, the Belfast Telegraph reports.

The cat was originally registered under the name ‘Tiger’ and had been taken to London where he became a stray in 2004.

It is still unknown how the cat crossed the Irish Sea to reach Northern Ireland.

Cats Protection co-ordinator Gillian McMullen told the Belfast Telegraph a call was made about a stray cat that was around a woman’s garden for several days.

Ozzie has been described as an affectionate cat. (cats.org.uk)

“The poor cat was starving but obviously had been cared for in the past because it was wearing a collar,’’ she said.

“I took it to Willow Veterinary Clinic on the Mahon Road, Portadown, where we discovered it was microchipped and this is where the mystery begins.

“The cat had originally been microchipped in Australia. Then in 2004 he turned up as a stray in a London vet clinic but no details were logged.”

Cats Protection volunteer Joy McCaw told the Belfast Telegraph that Ozzie has been described as an affectionate animal and larger than the average tomcat.

A photo was shared on social media to help solve the mystery. (Facebook)