Walking through those infamous huge iron gates, under the haunting sign 'Arbeit macht frei' (work sets you free) a terrified Gary Sokolov couldn't stop his legs from shaking.

Knowing he was about to witness the horror of his parents' past and desperate to honour them, the build up of emotion rendered him a wreck.

Ahead of the 80th anniversary of the liberation of the Auschwitz-Birkenau concentration camps on January 27, 1945, the only son of the 'Tattooist of Auschwitz', Slovakian Jew Lali Sokolov, (sometimes spelled Lale) was visiting the notorious death camp for the first time in memory of his late parents.

His pilgrimage to the site of the execution of six million of his fellow Jews was being filmed for a new Sky History documentary to be broadcast on the anniversary.

Many readers will already be familiar with his parents' incredibly moving love story documented in the 2017 best-selling novel "The Tattooist of Auschwitz" by Lale's former carer and housekeeper Heather Morris, and the TV mini-series starring Harvey Keitel last year.

But for the first time the couple's only son has now seen at first hand what his heroic parents endured and survived during WW2.

In an exclusive interview, Gary, 63, told the Express: "I was absolutely terrified to go to Auschwitz but I did not want to let dad down.

"I didn't know if I had the guts to do it but there were so many unanswered questions.

"As I walked through the gates though, under Arbeit macht frei, my knees were shaking so badly they had to stop filming until I could compose myself and get my legs to work properly. I was sobbing and felt like a coward."

Worse was to come for Gary as he was taken on a behind the scenes tour of camp and understand the full horror of what happened there 80 years ago.

"Walking through those gates wasn't even the hardest part. The hardest part was seeing the Crematoria. Dad had being saying over and over again, 'Crematoria Three' before he died.

"I don't think I have ever cried like that in my life. When I came out of there I could see the director was balling his eyes out too and had to call his wife.

"Afterwards I had no emotion left. I felt completely drained. It was emotionally horrific.

"But at the same time, walking in my parents footsteps was very special. I don't think I could have felt closer to them than I was there."

Gary's parents Lali and Gita met and fell in love as prisoners of Auschwitz-Birkenau.

Lali was forced to work as a tattooist at the camp, tattooing prisoners' numbers on their arms when the Nazis' exchanged new arrival names and identities for a number.

During his three years at Auschwitz, from 1942 to 1945, Lali , a 25-year-old Jew from Krompachy in Slovakia, would tattoo hundreds of thousands of prisoners, with the help of assistants.

One of those he tattooed was fellow Slovakian Gita Furman.

"I tattooed her number on her left hand, and she tattooed her number in my heart," Lali was later to tell author Heathe in the book about their love affair.
These forced tattoos, the numbers shaky and stark against pale forearms, have become one of the most recognisable symbols of the Holocaust and its' deadliest camp.

Lali first met Gita in July 1942 and their connection was instant.

He would send her letters, facilitated by a guard, as well as extra rations. They would meet in secret on Sundays, their only day of rest.

They lost contact in 1945 when she was sent to Mauthausen camp, just two days before the Russians advanced.
Lali later managed to escape, swimming the Danube to avoid capture, and travelled back to Slovakia on horseback where he searched for Gita and miraculously found her.

Desperate to get as far away from Europe as possible, they, like 127,000 Jewish refugees, mostly Holocaust survivors, moved to Australia, where their only son Gary lives today in Melbourne.

Gita died in 2003, aged 78, while Lali died in 2007 at the age of 90.

Gary takes up the story: "Before he died dad said he wanted to return to Auschwitz.

"Mum had been back to Slovakia before she died but dad had never been able to go back.

"I said 'dad really, are you sure?' but he said he needed to finally go back to apologise to all the people he couldn't save and I think he had a deep sense of guilt.

"I should have called up work the very next day and taken a couple of weeks off and just gone with him.

"Five weeks later he passed away so we never got the opportunity.

" I do have a real sense of regret that we didn't go together.

"So, when the offer of making the documentary came up I had finally the opportunity to make the apology on my father's behalf which was a big relief for me."

Before he visited the camp Gary was taken to Slovakia, visiting his parents childhood homes and his dad's school.

"I grabbed stones from both their villages so I could put them on their grave each time I visited.

"It's a Jewish traiftion to lay a stone on a grave.

"I am so glad I got to see all those places and meet relatives and people who knew them who are still alive today.

"If I had been to the camp first that wouldn't have been such a happy memory."

After visiting Slovakia Gary and the documentary crew travelled to Poland.

Gary said: "I was taken to areas that are not on the tour.

"I went to the area where my mum was in Birkenau. "The vastness of Birkenau was mind-boggling.

"The whole production. The way the Germans made sure there was absolutely no wastage, like even hair being bundled up to be sent to knitting companies.

"I was taken to dad's block, the gipsy camp and the punishment wing.

"I even saw the box they put my dad in in the punishment block. I snuck in there.

"It was so tiny. I tried to imagine three people in there.You had to stand up all night. You would hardly be able to breathe."

Gary visited the execution yard where prisoners would be shot in the back of the head, where their blood soaked through a metre deep under the ground.

He saw the appalling living conditions, the gas chambers, the conveyor belts which would transport the piles of naked dead bodies from the chamber to the crematoria.

He saw the railroads that brought in Jews from all over Europe and the tiny wooden carriages which held 80 people, many of whom suffocated before they even arrived.

"Seeing what my parents experienced at first hand has made me understand a little of what they were protecting me from by never talking about it.

"They would never speak to me about it growing up.

"Dad was so hardened in some ways, mum often very depressed.

"Dad was always looking forward though. He couldn't look back.

"I remember once coming home from school. I must have been about 12 or 13 and the house had gone up for sale and the car was being taken away. Dad had gone bust.

"I expected to go into the house and there be crying but mum was in the kitchen singing and cooking.

"She just said that when you had gone through what they had gone through you could cope with anything and she said dad had always looked after her and she trusted that he always would."

Gary is now a father himself to two daughters, Aviva and Marley (checking name spellings and ages) and took them to his parents graves so they could place the stones he had retrieved from Slovakia to place on their graves.

He added: "Since Auschwitz I am a different person now. I feel lighter and more at peace somehow.

Gary also says his Jewish identity is more important to him than ever now.

"My Jewish faith is exceptionally important to me because my parents survived and I do not want them to have survived for no reason.

"It is important to me that they have Jewish grandchildren in the world even though they never got the chance to know them.

"It is also really important to me to keep the religion going, to keep it strong."

Gary strictly observes the Sabbath, no phones, no computers, no cars.

Instead he plays and talks with his children, board games and trips to the park.

"I love spending time with my family with no distractions. I love Jewish traditions. We light a lot of candles.

"My religion is extremely important to me. It is the reason six million people died."

He feels a duty to keep new generations informed about the Holocaust and to challenge the deniers.

He added: "I have never met a Holocaust survivor who has wanted to talk about their experiences but I will continue to do so.

And he says, like his parents, he believes, however awful a situation is, particularly in war, there is always hope.

"My mum and dad were lucky to survive and I am the result of one of the most amazing romances in the most horrifc place.

"So I would say to all those people suffering aroudnthe world because of war, there is always hope. There will be better days."

* The Tattooist's Son: Journey to Auschwitz, Skjy History, Monday January 27, 9pm.