Cecchin, who disallowed a try that would have given Tonga an upset win, has told The Sydney Morning Herald he was in an Auckland bar when police rang to tell him they had contacted him and several family members that had been targeted.
He was advised not the leave the hotel and told he would be picked up and taken to the airport.
On his return to Australia, he was picked up by the Australian Federal Police.
He also flicked through his phone to discover more than a thousand "vile" attacks, the likes of which he had never encountered across his entire career.