The body of Louise Benson and her partner, both believed to be in their 30s, were found on a beach in Ericeira, a coastal town about 25 miles north of Lisbon, on Tuesday morning.
The report did not name the couple but said the woman was 30 and the man 40, although other reports gave slightly different ages.
Portugal's Correio da Manhã newspaper reported that the couple had died on the Praia dos Pescadores (Fishermen's Beach) near Ericeira, a picturesque seaside resort on the country's west coast.
The couple were in Portugal for a friend's recent wedding before the fatal cliff wall fall (pictured).
The newspaper reported that Rui Pereira da Terra, a captain with the local naval authority, told broadcaster TVI that authorities believe the pair fell when trying to recover a phone or to take photographs on the wall.
"Will be greatly missed by all of us who love them."
"It seems that [the victims] might be getting a "selfie", when they let the phone fall, leaned over to grab it and fell", he was quoted as saying.
Kearns was a part-time worker at an energy company in the Pilbara region of Western Australia while Benson, who was originally from Bristol, was a keen diver like Kearns.
The incident happened at Pescadores Beach as the victims - a man and a woman - were standing on a 100-meter beach wall.
A spokesperson for the DFAT said it was "providing consular assistance to the family of an Australian who died in Portugal".
The couple's bodies were taken to a medical centre while authorities contacted the Australian and British embassies in Lisbon.
"Owing to our privacy obligations we will not provide further comment". It is a popular spot and countless tourists upload their pictures of the enormous wall on social media.