While the strand is ranked as one of the most picturesque in Ireland it is known for a strong tide and powerful currents which sweep past the north Kerry coast.
A renewed focus has been put on the possibility that the victims were caught in a rip current, or a powerful fast current of water from a beach, which is one of the factors investigators are believed to be examining.
It is believed that Desmond ‘Dessie’ Byrne and his sister Muriel Eriksson went for an afternoon swim off Ballybunion shortly after 4pm on Thursday.
Mr Byrne's son was playing on the beach at the time.
It has been reported that when 62-year-old Muriel got into difficulty while swimming offshore, Desmond, who was also swimming, bravely went to her assistance.
However, he quickly fell victim to the same currents and also got into difficulty.
Sinn Féin councillor Robert Beasley who lives near where the tragedy unfolded on Thursday evening said while locals would be aware of a risk of rip currents at certain times, visitors to the beach would not.
“I asked the council on Friday morning to consider erecting signs on the beach,” Cllr Beasley said.
“It’s a well-policed stretch of beach but at certain times there are a risk of rip currents.”
Cllr Beasley revealed than the stretch of the beach where the tragedy happened was busy again on Saturday afternoon but that locals were very aware of what had just happened.
“I was in the town again today and it is at the forefront of everyone’s minds,” he said. “However, this is the first tragedy to occur here in more than 30 years,” he added, referring to a previous double fatality in mid-August 1992.
On that occasion, a father and his son from Co Clare were drowned after being trapped by the tide while exploring local caves. Tony McCarthy (50) and his son, Aidan (10), of Tulla, Co Clare, were on the last day of their holiday when they died.
Over the past ten years, five children were rescued from near tragedy off Ballybunion's beach in three separate incidents as the combination of strong tides and treacherous currents almost resulted in disaster.
Twice children had to be rescued in the open sea off Ballybunion after being swept out while playing with inflatable boats and toys.
In 2010, two children were rescued when they were swept away.
In 2013, a ten-year-old and an eight-year-old had to be rescued in the open sea after being dragged out by the current while using a ring-buoy.
Three years ago a young boy was rescued after getting into difficulty while swimming.
Meanwhile, following the tragedy that occurred on the Mens beach last Thursday, a book of condolences has been placed at the porch of SuperValu Ballybunion for the Byrne and Eriksson families.
“Our deepest and heartfelt condolences continue to go to both families,” Ballybunion Rescue said in tweet alongside the message regarding the book of condolences.
Funeral arrangements have also been announced for the tragic siblings who had only arrived in Ballybunion days before the tragedy.
Mr Byrne, who is originally from Athlone, has been based in Lecarrow in Roscommon for many years and worked as a carpenter and carpet-layer.
His older sister had been living in Malmo in Sweden over recent years but maintained very close links to Ireland.
Ms Eriksson will repose alongside her brother Dessie, at his home in Roscommon on Monday evening from 4pm until 8pm before removal on Tuesday morning to St John's Church, Lecarrow, arriving for Mass of the Resurrection at 12 noon.
Mr Byrne will be buried afterwards in the local cemetery while Ms Eriksson will be cremated on Wednesday at 4pm in Lakelands Crematorium, Cavan.
A funeral notice on RIP.ie said Ms Eriksson died “tragically, alongside her brother Dessie”.
The notice read: “Sadly missed by her heartbroken husband Kris, son John, daughter-in-law My, grandson Liam, brothers Kenny, Donal, Justin and Colm, sisters-in-law Maggie and Nong, Dessie's partner Paulette, aunts Kathleen and Kay, uncle John, nephews, nieces, relatives, neighbours and his many good friends.”
Mr Byrne’s funeral notice said he died “tragically, alongside his sister Muriel”.
“Sadly missed by his heartbroken partner Paulette, sons Dean and Josh, Paulette's daughter Regina and her sons Blake and Jace, brothers Kenny, Donal, Justin and Colm, brother-in-law Kris (Sweden), sisters-in-law Maggie and Nong, aunts Kathleen and Kay, uncle John, nephews, nieces, relatives, neighbours and his many good friends.”
“The Eriksson and Byrne Families thank you for your support at this time.”
Gardaí will prepare a file for a Kerry coroner's inquest next year.