Police have no idea as to the woman's true identity and do not even know how old she is.
Officers suspect she is connected to Botswana and London and could be part of an organised crime syndicate operating across the UK.
On a page set up to warn others, an apparent victim opens up about the string of lies she told him in order to get money.
According to the page, the woman claimed to be from Teddington, southwest London, and opened other accounts saying they were from Milton Keynes, Kingswinford, London and Loughton.
He said he gave her money for an art exhibition, to have some of her work framed, for import duty at an airport and for her food and hotel.
The blogger also claimed to have given her money while she was in hospital in Nassau, which he later said did not exist.
In a chat conversation he shared, she tells him her friend was not able to raise the money for her exhibition and she wishes she had known earlier.
Avon and Somerset Police have issued a photograph of the woman and will launch a Crimewatch appeal.
Detective constable Simon Da Costa said: "Within 10 months of them meeting online, the offender made multiple requests to the victim for money.
"The victim was manipulated into giving this money firstly by the promise of a relationship, then emotional blackmail and the promise of the return of his money, and finally by threats.
"Some of this money was paid into accounts with links to Bristol.
"We believe this scam is likely to be part of a wider criminal operation targeting lonely and vulnerable people online.
"We really need to find this woman, so if you have information about where she may be, or if you have also been a victim, please call us."
SKYPE CALL WITH A CON ARTIST
Below is a chat log detailing the first time the conwoman asked her victim for cash during a conversation on Skype.
Martha Cameron: 'I received very disappointing news from my friend in Nassau.'
**********: 'Oh dear?'
Martha Cameron: 'Told you I've been trying to reach her right? Well, she was supposed to help me with the registration fee of the exhibition.'
Martha Cameron: 'I've been working several weeks towards this and I was hoping she would lend me some money as I'm skint now.
Martha Cameron: 'I saw her email this morning that she couldn't raise the money.'
**********: 'Oh dear that's terrible.'
Martha Cameron: 'I know she has her own responsibilities but I just wish she had told me earlier.'
Martha Cameron: 'It made me cry this morning, because I've been waiting a while for her on this.'
**********: 'How much is the fee?'
Martha Cameron: 'Feels like my dream got crushed.'
Martha Cameron: 'It's $1000 and the deadline is near.'
**********: 'What if I raised the cash for you?'
Martha Cameron: '$1000 for regular and $1500 for VIP stands and accommodation.'
Martha Cameron: 'I would really appreciate it darling, it would mean a lot to me if you could do that'
Martha Cameron: 'You have no idea how much it would mean to me.'
**********: 'I can appreciate how much it would as its the thing you do in your life.'
**********: 'So it will be helping you life to achieve new goals'
Martha Cameron: 'Yes, it's a big step for my career'
Martha Cameron: 'I don't know if you can raise me the $1500 because i would have preferred the VIP stands as we are the first stop for clients. it'll boost my chances of making sales and also better services.'
Martha Cameron: 'I think its £980.'
**********: 'So the $1500 gets you a better place and then sorts out accommodation too.'
Martha Cameron: 'Yes darling.'
