Kevin Parle, 35, is wanted over the deaths of Lucy Hargreaves, 22, and Liam Kelly, 16, more than a decade ago.

A witness reportedly said he believes he had a drink with Parle in Perth, Western Australia, prompting Australian authorities to launch an appeal.

Parle goes by the nickname 'Hemp' and is currently listed as one of Spain's most wanted fugitives, AFP said.

He is known to have links to the Torrevieja area of Spain.

Ms Hargreaves' murder in 2005 was described as "one of the most brutal and callous acts" Merseyside had seen.

Three men entered her house in Walton on 3 August 2005, and shot her while she slept on the sofa.

They then set fire to the building, before Ms Hargreaves' partner and toddler daughter escaped the fire by jumping from an upstairs window.

Teenager Liam Kelly was shot on a Liverpool street in the early hours of 19 June 2004.

Officers believe the teenager was approached by two men from different directions, both armed with guns.

He tried to run away and was shot in the chest and arm as he tried to get into a house.