British intelligence sources gave Australian law enforcement the vital tip-off that alerted police to an alleged terror plot targeting a passenger jet, it has emerged.
According to Australian network 7 News, the country's Prime Minister Malcolm Turnbull was alerted to the plot on Wednesday prompting an escalation of security measures at Sydney Airport.
The UK's involvement in revealing the plot came to light on Monday as new developments were made in the investigation after officials reportedly recovered part of a meat grinder and a document for a Jakarta flight from a bin.
It also followed the arrest of four men during raids in the Surry Hills area of Sydney on Saturday amid allegations they had been planning to use a bomb disguised as a meat mincer and a device used to secrete gas to try and bring down a plane.
Reports on 7 News revealed officers had seized evidence including the flight number for a Jakarta to Sydney route from a bin at a home in Lakemba that police were led to believe was linked to the alleged plot.
The male suspects, reportedly two fathers and their sons, had been thought to have been targeting a plane bound to the Middle East from Sydney at the time of their arrest.
Security was stepped up at all major airports in Australia over the weekend after the alleged terror plot came to light.
Australian Federal Police commissioner Andrew Colivn said that details had been scant on the specifics of the attack, the location and timing but officers had become aware that "people in Sydney were planning to commit a terrorist attack using an improvised device" prompting a series of raids and arrests.