The 31-year-old told the Otago Daily Times Frandi had written a letter in reply to a personal column she had listed in a publication earlier this year.
"He did, honestly, sound too good to be true."
In that letter, Frandi described himself as having "GSOH" - a "good sense of humour - and gave his address and phone number for future contact.
The Eastern Southland woman said as part of their burgeoning relationship she had exchanged hundreds of texts, including several pictures, and the pair often texted late into the night.
After several weeks of non-communication, she decided to call him for the first time when he was named in connection with the grisly murder of a Czech tourist.
"I just saw his photo, and thought, 'that's him'.
"I felt so sick after reading the paper ... that could have been me."
It was revealed late last month police were hunting for the convicted kidnapper, shortly before he murdered Dagmar Pytlickova (31).
The bodies of Frandi and Miss Pytlickova were found in a forestry block near Waimate, where Frandi lived.
The woman said she was shocked by the news, which left her unable to sleep for several days and wondering what might have happened if she had called to meet him for the first time.
She had removed her advertisement from the publication, as well as another online dating site, on the day she found out about Frandi, and is now warning others looking for love to be careful.
"I am just going to stick to myself, I reckon."
NetSafe chief technology officer Sean Lyons said people were advised to do online background checking, including picture and information searches, on people with whom they might be interested in getting involved.
When meeting someone for the first time, it was advisable to meet during the day and even take someone with you, he said.
