Laughing and joking as they admire the glowing embers of the barbecue, a shaky home video shows Brenda Thomas and her sister Heila Kilian clearly delighted to be reunited after more than a year apart.

Glass of wine in hand, the sisters play the fool for the camera, dissolving into giggles as they revel in each other’s company.

But half an hour later, Heila was dead – shot through the heart by masked intruders who burst in on the family in their home on the outskirts of Cape Town.

Retired British engineer David Thomas, 67, caught the final moments of his sister-in-law’s life as he and wife Brenda, 61, hosted a barbecue in her honour.

In an emotional interview with MailOnline he told how he and his wife, along with close friend Shaun Vorster, 51, were bundled to the ground and tied up as victim Heila, 63, died from a single shot.

Father-of-two David was dragged into the darkness and had his head smashed repeatedly against a brick wall and had a gun put to his head and was told by his attackers they 'hate whites'.

Heila Kilian, 63, was shot through the heart when masked intruders burst in on a family barbecue that she enjoyed with her sister and her British brother-in-law

Retired British engineer David Thomas, 67, caught the final moments of his sister-in-law’s life as he and wife Brenda, 61, (both pictured) hosted a barbecue in her honour

The haunting final moments of Heila's life were caught on this home video as she was filmed embracing her sister Brenda just 30 minutes before being murdered in the garden (pictured)

David said: 'My feet and hands were tied up and then tied to each other and I was trussed up like a turkey and gagged and then this robber put his gun up to my head.

'He said 'I hate whites' and I thought that was it and was just waiting for the bang from the gun to kill me but it never came. But the beatings and threats went on for hours and hours.

'My wife and I are devout Christians and we bought this small holding to develop it into a venue for uplifting people through music and song and art in the image of how we both see life.'

David, a father of two from London, told MailOnline of his ordeal

South African born wife Brenda – who met David when she was working as a school teacher in Dubai and he was working for a US corporation – pretended to be dead and lay on the floor.

However the attackers beat her with a rock and put a knife to her throat and threatened to kill her as they tied her up and all three feared as the torture began that they would die that night.

'Even with a knife at her throat my wife was still quoting the scriptures to these men telling them that God still loved them – I have never seen anything like it she was just so brave.'

He went on: 'The four of us were enjoying a barbecue and having a drink and it was a lovely evening and then these men came round the corner and one of them just shot Heila dead through the heart.

'I didn't see it myself as I had been bundled to the ground and was having my head beaten against a wall and when I was threatened with knives and guns and was sure I was going to die.

'They had triangular yellow masks on under balaclavas and orange boiler suits and it was almost like they were in uniform.

'The three of us that were still alive were dragged in different directions and beaten and tortured with the threat of death from knives and guns and I didn't know if my wife was still alive.

David, pictured with Brenda, said: 'My feet and hands were tied up and then tied to each other and I was trussed up like a turkey and gagged and then this robber put his gun up to my head.'

The homestead where the family were enjoying a BBQ before the masked raiders turned it into a bloodbath (pictured)

'We do not have money here and I kept telling them that but they had information about Shaun and kept hitting him with a rock until he opened his safe and there was R40,000 in cash in there.

'They took that (£2,350) and two rifles and a shotgun and pistol and threw it into my bakkie which they drove off in and they were headed back to Cape Town judging by the way they were going'.

Brenda unknown to David had managed to untie herself and jumped over a steep ledge behind the house three metres onto the hard earth and begun running through the bush in the pitch black to safety.

David said: 'She ran a quarter of a mile through the harshest vegetation you can imagine with snakes and scorpions out there and jagged rocks and thorns and even got through a barbed wire fence.

'These five guys left after about two hours of putting us through hell and convincing us were going to die but then they left and Shaun said although tied up he was going to wriggle to the neighbours home.

'How he got there I don't know but he managed to wake them up banging on the door.

'They raised the alarm and the South African police turned up and when Brenda saw it was safe she was able to shout out in the dark and let them know where she was and was rescued.

David, from London, said: He went on: 'The four of us were enjoying a lovely evening and then these men came round the corner and one of them just shot Heila dead through the heart.'

'Shaun was brought back to the house and he told me that Heila had been shot dead. It was a single shot through the heart. She died instantly. She had not offered them any resistance.

'I assumed all the way through my wife was dead as well but what I found out later what with her being threatened with death with a knife and a gun and escaping is that she went through hell'.

The retired engineer waited until he was sure that the five men had left and wriggled into the kitchen and found a serrated kitchen knife he used to begin cutting through his bonds with.

David said: 'The next thing Shaun comes in and says : 'Heila has been killed but Brenda is OK'I was in total shock as Heila and Brenda were sisters and they were just so close.

'Brenda hadn't seen her older sister for over a year and was overjoyed when she had come down from Johannesburg and they were enjoying their second day with an evening braai.

'She has been taken away from us and from her wonderful family'he said.

Victim Heila was a mother-of-four with children Eugene, 45, Anton, 44, Marika, 43, Zane and Eugenie, 37, and was married to Hein, a retired South African police riot unit Commander.

The tough former police officer had stayed at their home in Springs, near Johannesburg, so that his wife could spend a fortnight away with her sister and was said to be devastated last night.

David said his wife Brenda (pictured) was praying for the men as they held a knife to her throat

David said last night: 'Brenda and I are coping OK but the tears will come at the funeral. My wife and I are a private people and devout Christians who only look to help and support others.

'There was no need for life to be taken as we were not able to put up a fight'he said.

David has two sons from a previous marriage Peter, 31, and Nathan, 34, who live in the UK and Brenda, who he married five years ago, has a son Brendan, 34, from a previous marriage.

The five farm attack suspects were caught refuelling the Bakki (station wagon) at a local petrol station and were believed to be heading for Cape Town which is about a four hour drive away.

Police spokesman Captain Malcolm Pojie said: 'Preliminary investigation and witness reports reveal the owner of a nursery and three friends were enjoying themselves at a garden braai.

'The barbecue was situated in the back of the house when they were accosted by five armed suspects whose faces were covered with balaclavas and all of them wore orange overalls'.

Witnesses said the men opened fire 'without warning' and Kilian was hit and died on the scene during the attack on Monday night this week.

Pojie said two male victims were then overpowered and handcuffed by the assailants but another female victim managed to untie herself and flee into the bushes and she was rescued later.

He said: 'The suspects meanwhile ransacked the house and broke open the safe and fled with an undisclosed amount of cash and four firearms as well as a collection of hunting knives'.

Capt Pojie said: 'Preliminary investigation reveals that the bakkie was later spotted refuelling at a petrol station indicating that the suspects were en route to Cape Town after this crime'.