“We all know what she's been going through the past few years with this terminal illness. Like anybody out there you have good days and bad days,” said Teap.
“She has just been through a rough time as of recent. She started a new chemotherapy session last week which has been pretty tough on her.
“She wanted me to share that with everybody because that’s why she’s not here today. She has already improved in the last two days which is great.”
Simply titled Vicky, the documentary - which is released in Irish cinemas next weekend - highlights how Phelan exposed the cervical cancer scandal, one of the worst women’s health scandals in Irish history.
It also highlights her personal efforts to stay alive by accessing the latest treatments for the disease.
This weekend, a portrait of Phelan was projected onto the GPO in advance of the film’s release.