Five year old Lara Lewis has died alongside her grandfather, named as Brian O'Dwyer (66) at a beach in Nazaré in central Portugal.
The two bodies were spotted in moderately rough seas along with the grandmother, named as Jill O'Dwyer, by a fishing boat, who managed to safely retrieve the woman from the water.
“The grandfather was already dead when he was hauled from the water. Emergency services attempted to resuscitate the child, but to no avail”, Nazaré Port Authority Commander Albuquerque e Silva said on Tuesday afternoon.
“The two victims, accompanied by the grandmother, went on a stroll away from the Salgado beach, which is under lifeguard surveillance, and it must have been during this period that they were knocked over and dragged in by the waves”, the Port Commander added.
The three victims were then spotted by two fishermen “who pulled them from the waves and notified rescue services”.
Paramedics applied first aid treatment to the woman, who was transferred to the Alcobaça Hospital from where she is reported to be in a stable condition and clear of danger.
The trio were on the beach with the girl’s parents Philip and Sian Lewis, who are said to be in a state of shock.
Mr. Lewis works University College London, where he is Professor of Remote Sensing - the science of using instruments in space to gleen information about the Earth’s surface through electromagnetic radiation.
The alert was sounded at 1:53pm on Tuesday evening and resulted in the deployment of ten fire and rescue workers, along with the members of the naval police.
The red flag has been raised at Salgado beach earlier that morning, due to the treacherous seas and strong tides.
Seas across Portugal were extremely rough the past few days, with one lifeguard at Carcavelos beach in Lisbon saying he had to save 23 bathers on Tuesday.
The number of people who have drowned off Portuguese beaches this summer has now climbed to eight.
A spokesperson at the Foreign Office said: "We can confirm the deaths of two British nationals earlier today in Portugal. We are providing consular assistance to the family at this difficult time."