Pop star Taylor Swift has become the target of an online campaign after an American artist posted an open letter to the singer on social media, accusing her of stealing her artwork.

Artist Ally Burguieres has taken to Facebook to call out the 26-year-old singer of using one of her artworks to promote her album without her permission or offering compensation.

In October 2014, in the lead up to the release of her album 1989 , Swift posted a picture of a hand-drawn fox with the song lyrics “They are the hunters we are the foxes and we run…” written beside it.

Ms Burguieres claims she is the original artist of the fox, which was signed by someone else in Swift’s post.

Arist Ally Burguieres has been trying to get Swift's team to rectify the mistake for more than a year. (Ally Burguieres)

Now Ms Burguieres has taken to Facebook to document her legal venture to gain credit for the picture from Swift.

“I received word that although she used a copy of my work to promote her latest album, Taylor Swift isn't interested in crediting me because—according to her team—her endorsement is too ‘valuable’,” Ms Burguieres posted earlier this month.

She followed up the claim with a letter addressed to Swift which has been shared more than 600 times since it was posted yesterday.

“I am a professional artist,” Ms Burguieres wrote.

“With years of work and support from customers, friends, and family, I have built a business around my designs.

“As a professional artist, I was astonished to see you use one of my most popular designs on all your official social media platforms as part of your promotions for 1989 .

“The design was a copy, and with someone else’s name signed to it. I was devastated.”

Yesterday Ms Burguieres posted an open letter to Swift on her Facebook page. (Ally Burguieres)

Ms Burguieres said at first she “took solace” in thinking it was an honest mistake.

“I thought if you only KNEW about the error, you would do what is in your power to make it right. I was wrong,” she wrote.

“After months of effort, I received an offer from you and your team that mentions no credit to me as the artist of the design, but does include payment of a ‘four-figure’ amount, with the stipulation that I must donate it all.

“Taylor, as a professional, would you agree to such terms from Apple, or Spotify?”

Ms Burguieres ended her letter by admitting she did not know how or if it would help her plight but told Swift she hopes to see her actions “fall more in life with the values you claim to hold”.

She was referring to the public claims Swift has made in regards to music sharing.

The singer famously stripped her entire backlog from Spotify at the end of last year, shortly after writing a piece for the Wall Street Journal about why she doesn’t support streaming services.

“Art is important and rare,” she wrote.

“Important, rare things are valuable. Valuable things should be paid for.”

Shortly after removing her music from the service, and as the hashtag #justsayyes, a play on her lyrics and a bid for her to return started by Spotify’s social media team, trended worldwide, the singer spoke to TIME once more about the importance of art.

“I think there should be an inherent value placed on art,” she said.

Australian feminist writer, Clementine Ford, shared Ms Burguieres’s letter on Facebook , imploring her to live up to her word.

“This is really disappointing,” she wrote.

“Come on ‪#‎taylorswift - do the right thing and don't be a hypocrite. Your art is no more valuable than anyone else's.”

Despite the calls for Swift’s attention it is likely Swift’s team, rather than the singer herself, is responsible for handling her albums promotional material and any legal issues.