Bizarre scenes unfolded in Sydney when an internationally notorious conwoman in her 30s allegedly tricked people into believing she was 14.

Samantha Azzopardi, 33, has been charged by NSW Police with false representation resulting in a police investigation after she allegedly presented to non-profit service provider JewishCare and led multiple agencies into a nine-hour investigation.

Azzopardi, who has used more than 40 aliases during cons in various countries including Ireland and Canada, told staff on Monday her name was Azzapadari and that she was a 14-year-old French girl.

In a statement on Wednesday, NSW Police said they were called to a property in Woollahra after concerns were raised about the girl's welfare.

"It will be alleged in court that police were told the girl was a foreign national and had recently arrived in Australia to stay with a foster family after fleeing abuse in her home country," the statement read.

"Exhaustive efforts were made by the NSW Police Force and multiple partner agencies to locate the foster family and investigate the family care and neglect claims.

"As part of these inquiries, it was established the 14-year-old was actually a 33-year-old woman, who was subsequently arrested at Waverley Police Station about 7.30pm."

Azzopardi appeared at Waverley Local Court on Monday and was formally refused bail. She will appear at the same court on Friday.

Azzopardi has previously posed as an au pair for families in Melbourne and Sydney. One of her previous employers was Perth Wildcats player Tom Jervis.

She told Tom and his wife Jazze Jervis that her name was Harper Hernandez, and spent a year with the family before taking off with Mrs Jervis's passport.

Her cons, for which she has been convicted, go all the way back to 2010, when she told authorities in Brisbane she was 14-year-old Dakota Johnson.

Authorities provided her with housing and help, but she was later convicted of forging documents and false representation.

In 2011, she told a family in Perth she was a troubled gymnast from Russia whose first name was Emily.

She told them she was 16 and that her entire family had died in a murder-suicide in France.

In 2013, she told authorities in Dublin, Ireland she had been sexually assaulted by a number of men. Her story made international headlines, but when authorities discovered she was lying, she was kicked out of the country.

In 2014, she told authorities in Calgary, Canada, that her name was Aurora Hepburn, but they quickly clued-on to the ruse.

A police spokeswoman said healthcare workers had "spent countless hours working on the alleged victim to establish the extent of her abuse and provide services for her recovery".

"We don't know exactly how she got here," the officer said.

"We are concerned about this happening somewhere else in Canada, or anywhere."

In 2017, Azzopardi posed as a 13-year-old schoolgirl named Harper Hart. She tricked staff at a Sydney school into allowing her to attend classes, but was later arrested and charged with four counts of dishonestly obtaining financial advantage by deception.

She pleaded guilty and was jailed for one year.

News.com.au spoke exclusively to a young American backpacker who crossed paths with Azzopardi in 2014 while holidaying in Australia.

Emily Bamberger said she was told a story that seemed unbelievable, but she had no reason to believe she was being lied to.

Azzopardi reportedly told her she was "royalty", and she had been kidnapped as a young girl. A series of bizarre events ended after Azzopardi convinced Ms Bamberger to get the pair fake IDs.

- Rohan Smith, news.com.au