Michael Lyddiard lost an arm and suffered facial disfigurement working as in explosive ordnance disposal and admitted he still walks down the street feeling ashamed.

The show probed seven returned servicemen and women with an array of confronting questions submitted by the public, prompting some candid responses.

But it was the question of what it was like to kill another human being that seemed to cut deepest.

“That’s probably the worst question you could ask anyone who carries a weapon,” Kieron Sewell, who served for 14 years in the Australian infantry, said.

Two other men in particular seemed distressed by the question, including one who recalled the killing of an elderly man and five-year-old boy in Iraq.

“There’s probably two that I regret,” Brad Fewson, a former infantry paratrooper of 16 years service, said.

"People don't go over there to kill people," 14 year army veteran Kieron Sewell said.Source:ABC

“I worked in Iraq as a private military contractor. We were travelling through Fallujah in a convoy and my rear gunner had seen a vehicle that was travelling quite fast.

“It kept picking up speed as it was going and then it turned the side street, coming straight at us. “I told my gunner to put its warning shots over, which my gunner did.

“He put the warning shots into the vehicle. It kept coming.

“A couple more warning shots. It kept coming.

“When we could see the car, I asked him early, you know, what could he see?

“It had an old man in it, he said. He hesitated, you know, after the warning shots, he hesitated and said, ‘What do I do?’

“And I said, ‘Fire.’

“I stuck the weapon out the vehicle. Just lit that car up. Just lit it up hard.

“No-one that I know is happy about ending a life. It never leaves you.

Iraq War veteran Brad Fewson recalls killing an elderly man and young boy in battle.Source:ABC

“What was that old man trying to achieve? I don’t know.

“I don’t know. And, yeah, I regret it, but it was still the right decision to make at the time.”

Michael Lyddiard, an explosive ordnance disposal veteran who served in Australia’s peacekeeping efforts in East Timor in that late 1990s, was still unable to go into much detail about an incident that still caused him distress.

“We drove into a crowd and we ... you know, you don’t stop,” he said.

“The vehicles got screwed up, a lot of screaming, a lot of yelling, a lot of people under vehicles. We’ll leave it at that.”

This is the second series of You Can’t Ask That, which enables curious members of the public to ask awkward, inappropriate or uncomfortable questions of a marginalised group each week.

In the past, groups that have appeared on the show have included, suicide survivors, ex-prisoners, Muslims and transgender people.

This week’s returned service men and women special, timed to coincide with Anzac Day, also canvassed an array of other issues, such as the mental health problems that can follow extensive service.

Michael Lyddiard lost part of his right arm and suffered facial disfigurement working in explosive ordnance disposal in Afghanistan.Source:ABC

Mr Lyddiard had an explosive device blow up in his face in Afghanistan, disfiguring his eye area and claiming part of his right arm, along with his thumb and forefinger on his left hand.

“I’m different. I’m not normal,” he said, wiping away tears.

“I walk down the street, sometimes ashamed, you know, ashamed and people not understanding who I am or what I’ve been through.

“You know, on Anzac Day, at least I can put the medals on my chest and walk up with my head up and be a part of something again, you know?”

Many spoke about lost marriages, battles with alcoholism and drugs and suicidal thoughts.

All spoke about the frustrations of returning to their normal lives.

“I don’t want to sound crass or crude here, but, you know, I saw a local woman picking corn out of human faeces to go back and recook it so she could feed her kids,” said 26 year infantry veteran Steve McCrohon.

“You go and you see a certain level of human suffering, I guess. You see a certain level of impoverishment. You come back to a world that is so far from that. People in the West are greedy.”

“Oh, you get the sh**s with the first world problems they’re bitching over,” agreed intelligence officer Alex Blane.

“I want to slap people in the face and go, ‘There’s other things going on in the world’,” Mr Sewell said.

“But you can’t. It’s socially inacceptable (sic).”