A Scottish author is searching for mysterious Nova Scotia fan.

Craig Robertson has enlisted the help of social media to #FindSadie, a Canadian woman travelling in Scotland with a copy of Robertson's latest book, The Photographer, in her bag in case she bumps into him.

If that happens, Robertson is keen to sign her book, buy her a coffee and have a chat with her.

"I don't know a lot. I know that she's from Nova Scotia, she's touring Scotland," Robertson, a best-selling crime fiction writer, told CBC's Maritime Noon.

The woman, whose first name is Sadie, was seen by Robertson's friend, actor David Kinnaird, on Wednesday in Stirling, a town of about 60,000 people.

Sadie thought Kinnaird was Robertson and asked him to sign her book.

"He (Kinnaird) presents ghost walks and history tours in the old part of the town. And she stopped him in the street and said that she was a big fan of his and 'would you mind signing a book,'" Robertson told Maritime Noon.

"Now David has done books and didn't think too much of this. But she pulled out a copy of The Photographer, which is my latest book. David, like me, has a bald head and a beard, and she thought David was me and David contacted me to tell me the story. And I said, 'let's see if we can find her.'"

Scottish author Craig Robertson's latest book is the The Photographer. (Craig Robertson's Facebook)

According to Kinnaird's description, Sadie is possibly in her mid-60s and has reddish bobbed hair. She was wearing a green jacket and may be travelling with her husband.

The two men set out to look for the woman.

"We haven't found Sadie. The search goes on but we feel we're getting closer and hopefully with your help, we can get there," Robertson said.

"I tend not to get involved in too many real-life mysteries, but I'm using whatever talents I have to try to track Sadie down."

Robertson has posted about his search for Sadie on social media, asking people in Stirling to keep an eye out for her because he'd like to sign her book "since she's gone to so much trouble."

Craig Robertson says he's posted about his search for Sadie on social media, asking people in Stirling, Scotland, to keep an eye out for her because he'd like to sign her book "since she's gone to so much trouble." (Craig Robertson's Facebook)

By Thursday, his post was shared about 460 times. Local tourist venues, bookshop and library staff are also on the lookout for Sadie. And local newspapers are running stories, as well.

"So everyone is keen to find Sadie. I hope she doesn't mind being looked out for, so hopefully she's OK with that," Robertson said.

The author said he loved the idea that Sadie came to Scotland and "just was confident she would bump into me and took the book just in case she did. So, that really tickled me, so that was part of what moved me to try and find her."

However, the window is closing in on Robertson's search for Sadie. He is travelling to Spain tomorrow.