The British Foreign Office is in touch with the Australian Department of Foreign Affairs and Trade about the deaths.
The couple had reportedly left Australia to see the world months earlier, and had recently attended a wedding in Portugal.
Their bodies were found by council workers who were sweeping the beach.
"It is with a heavy heart I have to announce that Michael and Louise were taken from us in a tragic accident in Portugal", Ms Kearns wrote, alongside a photo of the couple.
Authorities in Portugal say a couple on vacation plummeted to their deaths, possibly while snapping selfies on a seaside wall.
Their bodies were discovered on Tuesday morning on the Praia dos Pescadores (Fishermen's Beach) near Ericeira.
Perth man Michael Kearns died in the fall.
"Everything seems to indicate that the fall probably happened when they were trying to take a selfie", Pereira da Terra said.
He reportedly said to the Lusa news agency that "since we found a mobile phone on the wall, everything suggests the victims might have been taking a selfie".
'The Department has been in contact with the British Foreign and Commonwealth Office regarding the other person who died in the incident.
The beach at Pescadores is surrounded by cliffs and a 30-metre high wall covered in shrubs. "Owing to our privacy obligations we will not provide further comment", a DFAT spokesperson said.
Ericeria is a fishing and surfing town on Portugal's western Atlantic Ocean coast, 50km north-west of capital Lisbon.
Ericeira, a fishing town favoured by surfers, is renowned for its seafood restaurants and nightlife.
A British woman and an Australian man died in Portugal after falling from a 98-foot tall wall, according to authorities in the European country.