Four members of the family caught up in a shooting rampage in the French Alps were named by neighbours as businessman Saad al-Hilli's family, wife Iqbal, a trainee dentist, and daughters Zainab, seven, and Zeena, four.
Jack Saltman, whose house backs on to the family home in Claygate, said Mr al-Hilli had said something to him before he went on holiday that he would be informing the police about.
Mr and Mrs al-Hilli were both killed in the French carpark, along with an unidentified older woman, thought to be a grandmother. They had been staying at a local campsite.
Zainab was found in the road, having been violently beaten, and her younger sister found eight hours later, cowering under her mother's skirt in the car where the bodies were found.
Speaking to Sam Walker on the Richard Bacon Show on Radio 5 Live, he said: "I know one little thing which I am not prepared to speak (about) at the moment. I will tell the police about it.
"It was something Saad said to me before he went but at this stage I do not feel I can disclose that but I will tell the police exactly what he told me before he left."
He described his neighbour as "a massively helpful man, a wonderful engineer" who helped him repair household machinery when it broke down.
Mr al-Hilli's accountant said he believed the older woman was his mother-in-law.
Julian Stedman, Mr al-Hilli's personal accountant for the last eight years, said he had spoken to him the day he left for France.
Mr Stedman said: "The day he was going I was trying rapidly to get his VAT return done.
"He was rushing down to collect his mother-in-law from Reading. I think she was the person who was with them (the family)."
Mr Stedman said he did not know Mr al-Hilli personally but described him as a "family man" who shared his interest in caravanning.
He said: "I met him every quarter - he came round here to do his VAT return with me. I would occasionally go to his house to pick things up and see his wife and children.
"He was a very hard-working family man who loved his children.
"He never talked about what he did in Iraq, he has been in the UK for quite a long time. Most of his family are over here as far as I know.
"We had a mutual interest in caravanning. He used to go to France on holiday in his caravan, I did as well so we exchanged some information about caravans."
Mr Stedman said his client had not been on holiday in this area of France before.
The accountant said his son first put him in touch with Mr al-Hilli. In 2004, he began to do the accounts for Mr al-Hilli's company - Shtech.
The company dealt with computer aided mechanical design work, mainly in the civil aviation industry, Mr Stedman said.
Mr al-Hilli was the only employee and had worked with airline manufacturer Airbus on aircraft interiors, he said.
Mr al-Hilli set up the company in 2001 and got most of his work through industry contacts. The company was "doing well", Mr Stedman said.
According to the friend, known as James, Mr al-Hilli said his family moved to the UK in the 1970s after their mechanical engineering business was looked upon "unfavourably" by Saddam Hussein's Ba'ath party.
Speaking outside Mr al-Hilli's home, neighbour Jack Saltman said: "They are quite beautiful kids and so well behaved. He was an extraordinarily nice man and helpful. His wife was a delightful person and I can't think why anybody would want to harm them.
"My wife is in floods of tears, she's heartbroken. When I stop to think about it I'll cry for those little kiddies. What sort of life are they going to have now?"
SEE ALSO
Was Killing Of British Family 'Car-Jacking' by Armed Bandits?
Cyclist Killed In British Car Shooting Named
French Alps Shooting: Three British Dead From Gunshot To Head, Fourth Death Unexplained (PICTURES)
He said Mr al-Hilli had said they were going to France for around a week-and-a-half to try to "get a bit of extra holiday in before the kids went back to school".
Mrs al-Hilli, he said, was a trainee dentist working at a practice locally.
"His two daughters were absolutely gorgeous, they were beautiful little girls," he added.
"Zainab, the elder girl, highly articulate, highly intelligent girl. The little girl was vivacious, full of life, a really bubbly little girl.
"They used to play together in the back garden and when I was working in the garden they would always come over and have a chat."
A British passport has been linked by police to the driver of the car peppered with bullets at the beauty spot in the Haute-Savoie region. A Swedish and an Iraqi passport were also found.
Neighbour Lorna Davey said her daughter attended Claygate Primary School with Zainab, while Zeena was due to start at the school this year.
She said: "They were very pretty, smiley little girls and a very nice, happy family.
"I'm shocked. They've obviously been extremely unlucky."
Ms Davey said the family would often go on holiday in their caravan and had been away on their latest trip for at least three weeks.
Mrs al-Hilli took denistry exams in the last few months, she added.