The actor joined the adults-only platform last year, saying she had done plenty of men’s magazine shoots over the years but didn’t feel like she’d had much of a say in them and that it was “cathartic” to take back control.
However, Hollyoaks then said cast members were not allowed “to be active on certain 18+ websites” and confirmed Dunn was leaving the show.
The star has now shared two very similar images side by side on Instagram – one that was in a national publication and one that she shared on OnlyFans – to show how her latest images aren’t much more risque than ones she’s done before.
“Two almost identical photos taken just under 4 years apart,” wrote the 40-year-old.
“The first photo: Arranged by someone else for a national publication, style of shoot decided by someone else, any editing/photoshop done without my approval, copyright of image (of me) owned by someone else, exclusive interview as agreement of shoot, no financial benefit to myself (but usually a payment is made in this type of agreement).
"The control, power and decisions in someone else’s hands.”
She went on: “The second photo: Taken by me for my OnlyFans platform, choice of image decided by me, zero editing or photoshop, copyright of image owned by me, despite no interview necessary for this particular shot when I do interviews now it’s because I want to, financial gains controlled by me and go to me.
"The control, power and decisions made by me.”
“Interesting,” she said, adding hashtags including “#knowyourworth” and “#takingbackcontrol”.
Dunn was cast as Hollyoaks’ Mandy Richardson in 1996 and played the character on and off in several stints on the soap.
Confirming her exit, a spokesperson for the show told Yahoo: “Hollyoaks is a youth-facing drama with many young viewers, who follow our cast very closely, both in the soap and outside of it.
“We take our responsibility to our young audience very seriously and therefore the show does not allow any Hollyoaks cast members to be active on certain 18+ websites.
“We had hoped we could reach a resolution with Sarah that would allow her to remain in her role as Mandy, but we respect her choice to continue to produce content on OnlyFans.
“In the past four years since her return to the show her legacy character has been an integral part of some our most important storylines and we will be very sad to see her go.”
Watch: Hollyoaks Soap Scoop! A controversial protest takes place