Ghahraman is in a relationship with NZ comedian Guy Williams, who Matafeo once dated.
"MPs aren't involved in organising party events or arranging speakers," a party spokesperson said.
"Unfortunately, this seems to be the result of a miscommunication within the party. We are more than happy to discuss this with Ms Matafeo personally."
In her earlier tweets, Matafeo attached a screenshot of an email she wrote claiming it was Ghahraman who asked her to step down as MC. She wrote she had reached out last week to find out why she was asked to step down.
"Yesterday I was notified I have been asked to step down as an MC at the upcoming Green Party launch, at the request of Golriz.
"I'm unsure why this request was made, as I have had very little interaction with Golriz in the past few years," she wrote.
Matafeo then appeared to hint at the fact she may have been removed as speaker due to previous ties with Williams and Ghahraman: "The only possible reason it could be is so petty I wouldn't dream of suggesting it."
Following up her posts on Twitter this morning, Matafeo shared a petition from the Green Party calling for support for their Poverty Action Plan.
"This makes me feel happy and hopeful."