The defining feature of Rachel's first real relationship was that it was very normal.

Key points: It is becoming more and more difficult for people to disappear as our digital footprints expand, according to investigators

It is becoming more and more difficult for people to disappear as our digital footprints expand, according to investigators Rachel says her first boyfriend faked his own death, escaping several debts

Rachel says her first boyfriend faked his own death, escaping several debts Rachel did not know her ex-boyfriend was alive until she ran into him at a local restaurant

She was 18, and her boyfriend Alistair* was 21. He was the chef at a local pub, where they both worked.

"He was really attentive, nice, like really not odd. I think that's what's relevant," she said.

About three months into the relationship, Alistair came home from a night out with a broken hand. He said he got it during a fight that wasn't his fault.

It meant he couldn't work for a while and Rachel said he borrowed about $1,000 from her to help make ends meet.

They broke up a few months later, not over anything significant — she was young and fickle, and she decided to end things.

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"It was not like anyone cheated or anything, there was nothing catastrophic," she said.

Alistair paid her back $300 but stopped replying to her texts when she asked for the rest.

Rachel said friends of his soon told her his things had started disappearing from the share-house he lived in.

"Furniture was gone, bed was gone, everything was gone," she said.

"The initial story was he'd gone to rehab in Queensland," she said, but she'd never had the impression he was a drug user.

Rachel started comparing notes with his other friends and found out he owed them money too. From what she could tell, he owed about $2,200 in informal personal debt.

"The moment we went 'OK, he owes everyone money', the anxiety and urgency of the situation ramped up," she said. "The story was falling apart really, really quickly."

Alistair's death

Rachel received the worst news possible — a friend called to say Alistair had died.

"It sounds stupid in retrospect, but you don't have any reason to question it," she said.

"If I called you and told you my mum died, you wouldn't be like, 'give me a death certificate'."

Alistair's mum told his friends her son had been murdered, said Rachel, because he owed money to a bikie gang.

Rachel said that at the time she didn't want to know all the details, her approach was just to "grieve in her own way and move on".

And she did.

Rachel said she was told Alistair was murdered by a bikie gang. ( Unsplah: Arnaud Mesureur )

Until two years later, when she was hanging out with her best friend at a family restaurant in the town they grew up in.

"I remembered that his brother also worked there," she said. "I went, 'I haven't seen him in ages, and I'd like to say hi'."

Rachel and her friend asked the waitress if he was working and she told them "no, but his brother is".

It didn't seem possible, but when she asked which brother, the waitress told her it was Alistair.

"I just went into shock."

Then she had an idea and asked the waitress to check if he could come out and see her.

"Next thing I know, manager's over [to ask] 'is there a problem here?'"

He asked them to leave.

Outside in the car, the two women debated what to do next.

At a loss about their options, they decided to go to the police.

"I was basically told by the police that it was my word against his that I'd ever even given him money," she says.

According to Rachel, she was told there was nothing they could do.

The night only got stranger from there.

They tried calling the restaurant and asked to speak with Alistair, and were told no-one by that name worked there.

Only moments later, Rachel received a text message from Alistair's mum, who years earlier had been the one to deliver the details of his death, complaining the "scene" they'd made had lost Alistair his job.

How hard is it to disappear in 2019?

Tens of thousands of Australians disappear every year, but disappearing comes in a few different shapes.

Some people slip off the radar by mistake, others meet with foul play, and others disappear very deliberately, according to Steve Wallis, the Managing Director of SWI Recoveries and Investigation Group.

"It's a slow process to totally disappear," he said.

Steve Wallis is what is sometimes called a "skip tracer" and is often tasked with finding people who have disappeared. ( Supplied: Steve Wallis )

Mr Wallis is what is sometimes called a "skip tracer".

"If someone is very serious about disappearing, the one thing they've got to be is patient, and they've got to be very, very committed to it," he said.

In his line of work, he hears of people who will, for a fee, illegally facilitate that process by creating a new, forged identity.

"But it costs a lot of money, and it takes 12 to 18 months," he explained.

"These people operate from overseas and we're talking six figures sums to make it happen".

He said an easier path, available to the "average" person who wants to disappear, is to do it gradually.

"People misspell my name all the time," he said. "You often get cards or some kind of connections with the wrong spelling on it.

"Collecting that kind of information to create another identity is another way of doing it."

Moving overseas, to a less developed country than Australia, can also aid the process.

He said only people with a very specific personality profile are capable of pulling it off.

"If you really wanted to disappear, it wouldn't be overly difficult," said Mr Wallis.

"You've got to lose contact with your family and friends, you've got to be a recluse," he said. "You've got to lie continually to people."

Steve Wallis said being an older person also makes it easier because the person's digital footprint within Government databases will be smaller.

"If you were born prior to, say, the 1960s, your footprint, unless you've created one, is pretty much non-existent, because there were no real records back that far," he said.

Although it's still possible, Mr Wallis believes it is becoming more and more difficult to disappear as our digital footprints expand, and surveillance technology improves.

"A lot of the time, it just comes down to budget," he said.

He said Alistair's case is a very unusual one.

Mr Wallis's theory is that ironically, Alistair's relative success in disappearing, at least for a time, probably has a lot to do with the fact he wasn't in very much debt.

"If the money was a lot more, they may have pursued it a little bit harder and conducted some further investigations," he said.

Coming face to face with Alistair

After the night at the restaurant, Rachel gave up on recouping her money or confronting her ex, but a few years later, she bumped into Alistair again.

This time, at a different restaurant in the same area.

She says she recognised him straight away and tried to strike up a conversation while he was on his way from the freezer to the kitchen.

"We made eye contact, and you could see he recognised me," she said.

"I was like, 'long time no see!' And he went, 'Oh yeah, it has been a long time."

She said he feigned confusion and didn't recognise her, then she angrily asked him about the money she was owed.

He mumbled a denial.

Rachel wishes she'd had a chance to ask him why faked his death or where he'd disappeared to, but the encounter was fleeting and strange.

"If I'd sat down with him properly, yeah, I would have had questions.

"One or two."

*Some names have been changed for legal reasons.