LONDON — It's the most popular podcast ever made — and now the global phenomenon that is Serial is coming to the BBC.

The first episode will air on BBC 4 Extra Sunday, with subsequent episodes broadcasting daily until it catches up with the United States.

The series finale will be broadcast on the same day as it goes live for U.S. audiences. The British broadcast is the first time Serial, which is produced by WBEZ Chicago, will be aired on radio.

“We know we already have tons of Serial listeners in the UK but we love that the BBC will help us reach many many more than we ever could with podcast alone," Ira Glass, the editorial advisor for Serial, said.

The nonfiction series, a spin-off of NPR's This American Life, has been enthralling audiences since it debuted in October, landing it the No. 1 spot in the iTunes podcast charts and becoming the fastest ever podcast to hit 5 million downloads.

Serial, hosted by Sarah Koenig, investigates the harrowing story surrounding the murder of a Baltimore high school student Hae Min Lee on Jan. 13, 1999. Currently, Adnan Syed, Lee's ex-boyfriend from Baltimore County, is serving a life sentence in prison for the murder, but he insists that he had nothing to do with her death.

The podcast has been released in the form of one episode per week, on Thursdays, instead of in one fell swoop. Producers have explained that the team is still pinning down information, doing interviews and following leads.

"So when you listen each week, the truth is that you’re actually not all that far behind us," producer Dana Chivvis said in a blog post in October.

Serial will air daily at 9 p.m. on BBC 4 Extra, starting on Sunday.