As an anchor for the Six O'Clock News, Natasha Kaplinsky is used to breaking harrowing stories while keeping her cool.
But telling her dad Raphael the shocking revelations she had uncovered about his relatives was the toughest and most emotional conversation of her life.
Natasha learned the horrific truth about the fates met by members of his Jewish family during the Second World War while filming the BBC1 show Who Do You Think You Are?
How his cousins, girls aged just nine and two, had been killed by Nazis using their bare hands.
How their mother had been murdered. How on discovering the brutal massacre of his family, his uncle Abraham took his own life.
And how his grandparents had been burnt alive in a synagogue.
Natasha's grandparents had shielded the truth from Raphael - for them the horrors were too deep and too vivid to be recounted. But now the 60-year-old economics professor was finally hearing what had happened from his daughter.
"It was a peculiar responsibility," says Natasha, 34, quietly. "He was so emotional. Very shocked and very upset... It was not the easiest thing I've ever done.
"It confirmed everything that everyone suspected, but the details were different. And the fact that I'd seen where some of them may be buried, and seen the death certificates and where it all happened - it made it more real." Understandably, this was one conversation she did not want to have in front of the camera.
"The plan of the programme is that you go off and find out things, then you come back and tell your family what you've found," she explains. "But I told the director I wasn't prepared to do that.
"I know this is reality TV, but it was a step too far. I didn't want to have a camera trained on my father's face as he found out what had happened."
The programme will be broadcast next Thursday and, at times, Natasha's own grief is plain to see.
"I just couldn't help myself from crying," she says. "It happened a number of times, I was very emotional. At one point I walked off because I was so upset and they didn't follow me with the cameras - I couldn't have handled that.
"I'm quite nervous about crying. It will be a change for people to see me with smudged mascara dripping down my face. But that's much more who I am.
"As a newsreader you can't let it show when you're all choked up, even though I often am. You have to be impartial and dispassionate and not show any emotion. After a while I suppose people think that's the kind of person you really are - hard and uncaring.
"So to be seen as a bit more myself is positive, but worrying. Still, Jeremy Paxman cried. So if he can cry, I can cry, right?"
It is no wonder she shed tears after hearing what befell her paternal relatives in the Holocaust. Natasha traced her dad's family back over the last century to a village called Slonin, in Belarus. Her grandparents left the region in 1929 for a new life in South Africa, where Raphael was born, but other relatives remained.
And it was in Slonin in 1942 that they felt the full force of Hitler's ethnic cleansing.
For the show, Natasha visited the area with her second cousin Benny - his dad Izak Kaplinsky only escaped becoming a victim of the Nazis because he was a doctor.
The cousins are shown the death certificates of their relatives and visit the synagogue in which their great-grandparents met a terrible end. They also learn that Izak worked tirelessly for the Jewish resistance after his life was spared.
"Those five days in Belarus were horrendous," says Natasha. "Back at work people were asking if I'd found any skeletons in the cupboard. I said I'd discovered too many really terrible, sad, heart-wrenching things.
"I sat in the newsroom and thought, 'What am I doing?' I was really traumatised by it." But she had no idea at the start of the horrors she would uncover.
"In one of the preparatory meetings I asked if they'd found any terrible stuff and they said no, not that terrible," she says.
"When I found out that children - members of my family - were pushed out of windows and ripped apart by Nazis with their bare hands, I wondered how much more terrible could it be?"
Her journey did have some upbeat moments, though. Natasha learned that her grandfather, who told tall stories, was telling the truth when he said one of their ancestors was the apothecary to George III. She also discovered that her father organised the first student protest against apartheid in South Africa.
Raphael disagreed with a decision not to let a black lecturer join the university and took action. When threats were made against him, he had to flee the country in 24 hours.
"Finding out that my dad was really a hero was a brilliant moment - I was so proud," says Natasha. "He made a stand and then had to leave and wasn't able to return for 20 years.
He was always modest about it, saying he played a small part in a big struggle. But to have led the first sit-in for students in South Africa, and for his life to be in danger, I have such respect.
"I'm glad I made Who Do You Think You Are? - it was a gift for the family. Here I am as a journalist always looking at stories and yet I'd neglected to look at my own.
"I hope that our story will help other people understand a bit about the horrors of what happened such a short time ago."
Even so, she was glad to get home to London and her husband, investment banker Justin Bower.
It was love at first sight when they met in 2005 at a party to launch a wedding-list service. Justin had no idea who she was, which only made him more attractive to Natasha. They got engaged after a six-week romance and wed six months later.
Their low-key nuptials were a very private affair, and Natasha has never spoken about her big day, or her love for Justin - until now.
"The bizarre thing is, before I'd even spoken to Justin I knew I was going to marry him. I was just struck," she says.
"I was wearing a ballgown because I was working somewhere else that night. He thought, 'Poor love, she's misread the dress code'. He thought I'd come in black tie and everyone else was in jeans. He felt sorry for me."
They had lunch two weeks later then met for a cuppa a few days after that (Natasha is teetotal).
Over their peppermint tea, they decided to go on holiday. And by the time they were sunbathing in the Maldives, he had bought her a £10,000 engagement ring.
"It really was a whirlwind," she says of their romance. "It was just one of those things. We met at the right time and I just knew I was going to be his wife."
Although she says married life is "just amazing", the wedding day left her a nervous wreck.
"I was petrified about walking down the aisle," she says. "So I picked the church with the smallest aisle I could find. I wanted to take two steps and be at the top. I was so nervous. Everybody says your wedding day will be incredible but I just thought I was so happy to be marrying Justin I didn't mind if it was great or not.
"In the event it was the best day I've ever had, truly fantastic."
When it came to the first dance at their reception at posh Babington House in Somerset, the bride sensed that her guests expected to be wowed. Well, she has starred on Strictly Come Dancing.
"Everyone thought we were going to whip around the dancefloor and be incredible, but we tripped and stumbled around like anyone else," she says.
"My husband can dance but in quite a different way to a professional ballroom dancer. It was a shock going back to dancing in a normal way."
Children - my relatives - were pushed out of windows and ripped apart by the Nazis
Who Do You Think You Are? BBC1, Thursday September 6, 9pm