Bob Odenkirk was rushed to hospital after collapsing on the set of Better Call Saul in New Mexico.
According to TMZ, the actor was surrounded by crew members when the incident happened, and an ambulance was immediately called.
The reason for the collapse has not been disclosed, and the 58-year-old is still in hospital receiving medical care, reports Variety.
The sixth and final season of the Breaking Bad spinoff, which centres on Bob as lawyer Jimmy McGill/Saul Goodman, is currently in production.
In an interview with James Corden earlier this year, the Emmy nominee said at the time that he had no idea where the story will go in its final season.
"I like to be excited like a fan or an audience member because this show, similar to Breaking Bad, these writers figure out ways to do something you didn't expect, but that makes perfect sense. I don't know how they do it, but they do it over and over, and I look forward to seeing where we end up."