There's been another case of green chicken. (And apparently, it's perfectly safe.)

When NSW woman, Kylie Mason, began carving up the Coles chicken she’d roasted for dinner on Tuesday night, she spotted something that made her stomach turn.

A large patch of the flesh inside was green. Vividly, unmistakably green.

“I was in shock,” the Lithgow woman told Mamamia. “I’m very [wary about] chicken to start with. If there’s a tinge of pink I will not eat it, if there’s the slightest smell I will not cook or eat it.”

Horrified, she posted a photo of the product to the supermarket giant’s Facebook page: “Thought I’ll do a baked chook for dinner last night, unfortunately we couldn’t eat it,” she wrote.

But it turns out she actually could have.

A Coles spokesperson identified the green flesh as the product of something called Deep Pectoral Myopathy, more commonly known as ‘green muscle disease’.

According to Poultry World, DPM is the result of a lack of oxygen reaching the chicken’s muscle, due to improper blood supply around tissues or blood vessels. This can occur when the bird excessively flaps its wings.

The result is a greenish lesion, which - though unsettling to look at - doesn't pose any food safety risk for the consumer.

"If the chicken has been consumed, it is not harmful, but this is not how we want our chicken to reach you," a Coles spokesperson wrote on Kylie's post. "We have strict quality standards that our poultry partners work to and this chicken should not have been packed.

"We are sorry that on this occasion it has been missed and encourage you to return the product to your nearest store for a full refund."

Despite assurances the chicken was safe, Kylie was relieved she spotted the green meat before serving it.

"When Coles told me it is perfectly fine to eat, I nearly vomited in my mouth," she said. "It has turned us off chicken for quite some time."

She said staff at her local Coles were just as shocked by the product, and refunded her purchase - no questions asked.

It's not the first time a Coles customer has encountered the problem. In June, Victorian shopper Jamie Ferguson discovered a patch of bright green flesh on the raw free-range chicken breasts she'd purchased from her local supermarket.