Rosanna Arkle has claimed her boxing opponent Jaime Ridge is ignoring instructions to lose weight ahead of their bout.

Ridge and Arkle, star of TV3 show The GC, will go toe-to-toe during an undercard match at the Godfather of Fight Nights in Auckland on July 5.

In a round of pre-bout trash talk, Arkle today claimed in a post on her Facebook page that Ridge had failed to lose five kilogrammes ahead of the fight.

"Pretty f****d off finding out that my opponent has completely ignored instructions to loose 5kg for our fight while ive been striving to get from 52kg to 55kg [sic]," she wrote.

The post was later deleted.

Ridge's mother Sally Ridge has come to her daughter's defence, calling comments about her weight "disgusting".

"Losing weight is not Jaime's number one priority, she's a healthy young kid, why would she need to lose weight? She's not doing this fight to go on a blinking diet," she said.

"I am just absolutely shocked and Jaime's really upset about it, and clearly I'm really upset about it as well."

Her daughter was training seven days a week for the fight, she said.

"She is 100 per cent focused and I take my hat off to her and it's really sad that it's come to this because she's put 100 per cent into this and I think it's incredibly unfair that it's come to this."

Arkle could not be reached for further comment.

- © Fairfax NZ News