Jenenne-Ann Allen vanished at 31. Now it's believed she's been living a double life.

It’s been nearly 14 years since Australian woman Jenenne-Ann Allen disappeared. She was 31, a nanny, living and working in London on a four-year ancestral visa.

But in 2003 her bimonthly calls to her family suddenly stopped, she became uncharacteristically absentminded, then in September that year she was seen for the last time, moving out of a friend’s home in South Croydon.

“[That friend] mentioned some things that made me think Jenenne may have been having some sort of breakdown,” the woman’s mother, Margaret Law told Marnie O’Neill of news.com.au.

“Sarah said she had been a bit scatty and had lost her passport and her phone. They seem like small things but they were so unlike Jenenne… really out of character.”

Each year passed without news. There were no calls, no sightings, neither police nor the Salvation Army could locate her.

But it seems she hadn’t, in fact, gone all that far.

A recent investigation by Britain's National Crime Agency established that as recently as two years ago Jenenne-Ann had been working in the office of a taxi company in northwest London, a position she is believed to have held for several years despite not being a British citizen.

But the now 45-year-old has since moved on, and her whereabouts are, once again, a mystery.

“We know Jenenne-Ann was working in Kilburn in 2015, so she may still be in the area," NCA officer Guy Wicker told local media in April. "All anyone wants is to know that she’s safe and to offer her support if she needs it.”

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While Margaret is 'haunted' by her daughter's decision to disappear, she is confident that Jenenne-Ann will one day come back to her.

"Remember Jenenne, that we will always love you and we’ll always keep looking for you,” the Perth woman told news.com.au.

“We just want to know that you’re fine and happy and you have two nieces and a nephew who would dearly love to meet you.”

If you have any information that could assist authorities in their search for Jenenne-Ann Allen, please contact UK organisation Missing People anonymously on 116 000, email 116000@missingpeople.org.uk or visit its website here.

She is 164cm tall, with a medium build, hazel eyes, brown hair and a distinctive mole above the right-hand corner of her mouth.