An Australian woman has revealed how she was swindled out of $37,000 by scammers pretending to be television star Alex O'Loughlin. 

The 45-year-old woman, who went by the pseudonym known as Sonia, said she was contacted in 2020 by a Twitter account with the same name as the 46-year-old Hawaii Five-0 star. 

But the account was a fake, completely unknown to O'Loughlin, with the fraudsters using clever tricks to form a relationship with the woman and convince her it was genuine. 

The real O'Loughlin, who was born in Canberra, starred on the hit CBS show for its entire 10 season run from 2010 to 2020 and is based in the US. 

There is no suggestion O'Loughlin is in any way connected to the scammers.

'I look back at it now and think about how stupid I was,' Sonia, from country NSW, told 9news.com.au this week.

The scam began when she was contacted in November, 2020, having mentioned on Twitter that she liked Hawaii Five-0 and followed some fan accounts of the show.

At first, she said the account seemed to be gauging her viewer's perspective of the program.

'The messages were all about the show and what I liked about it, what I thought of the last two seasons and that kind of stuff,' she said.

But eventually she was asked more personal questions about her life.

Initially skeptical, Sonia tested the person she was speaking to by asking questions only O'Loughlin would know such as his real name, which she said he knew immediately despite it being something you 'really need to dig for'.

Their conversation, shepherded by the scammer posing as O'Loughlin, moved from Twitter to WhatsApp and gradually became flirty.

He told her his marriage was in trouble and he was considering getting a divorce and settling down back in Australia and that he was developing feelings for Sonia.

After a month of constant messages and nearing Christmas, the fraudster said he bought her a present and sent through photos of an item worth $360,000 he claimed he purchased from a New York jeweler. 

Sonia said she felt so flattered she agreed to the 'customs fee' of $8,500 to get the present privately couriered from overseas. 

When it never arrived, Sonia began to get suspicious but the fraudster was extremely apologetic and convinced her they had also been ripped off by the jewelry not arriving.

He then offered to transfer her the cash amount the jewelry was worth to make it up to her but and directed her to the website of Trust Universal Bank - a fake institution.

When she asked why he couldn't just transfer the money directly into her own current account, he said it would be too noticeable.

'He said he didn't want his wife to find out about it as they had a joint account,' Sonia said.

So she made an account using her own ID documents and soon after received an email saying someone had deposited $502,560 into it.

She logged into her account through the website and sure enough the money appeared to be there - but when she went to withdraw it she was asked for a transfer code.

All part of the elaborate scheme, she found out the transfer code would require a fee of $8,000, which she paid, and then another transfer fee of $20,500.

When the system then asked for yet another $12,000 in fees she said she did some sleuthing and found out their logo was from the slightly differently named Trust Bank - a legitimate business that she called and was told there was no record of her account. 

She described the moment she realised it was all a con as 'like being hit with a baseball bat'.

She added that she has since spoken to other victims of the same scam on fan sites of the actor - some who have lost hundreds of thousands of dollars.

O'Loughlin's Australian representative, US agent and lawyer are reportedly aware that the scam is circulating.