Serial podcast: Who is Bowe Bergdahl and what is his story?

Bowe Bergdahl

It's expected the new season of cult podcast Serial will investigate the story of US soldier Bowe Bergdahl, who spent five years as a Taliban hostage.

The 29-year-old army sergeant was captured in Afghanistan in 2009 and held prisoner for five years after leaving his base.

He was set free in May 2014 as part of a prisoner exchange with five members of the Taliban being held at Guantanamo Bay.

But his case raised many questions.

Some fellow soldiers claim that Bergdahl deliberately "wandered away" from his unit in June 2009.

And on 25 March this year the US military announced that Bergdahl had been charged with desertion and "misbehaviour before the enemy".

Did he walk away from his base?

Bergdahl was serving with an Alaska-based infantry regiment in Paktika province near the Pakistani border when he went missing.

It is said that he had grown disillusioned with the US army's campaign in Afghanistan.

Military officials think he was located across the frontier in Pakistan for most of his captivity, reportedly held by the Haqqani network, which operates in the Afghanistan-Pakistan border region and is allied to the Afghan Taliban.

Bowe Bergdahl in captivity
Image caption Bowe Bergdahl photographed in 2010, during his time as a hostage

A Pentagon investigation found that Bergdahl left his post "without authorisation", according to an interview given to the Associated Press news agency.

A military report said that he had walked away from assigned areas before, in California, and previously in Afghanistan, according to the New York Times.

Many have branded him a deserter and called for him to be punished.

Two new stories

Serial comes from the makers of This American Life, a weekly public radio show broadcast in the US and itself a highly successful podcast.

Production manager Emily Condon told Newsbeat the team is working on two series at the same time.

"Over the last few months they've been reporting on a variety of stories for both seasons two and three of Serial," she said.

Last time Serial told the story of 17-year-old Hae Min Lee, a high school student found murdered in 1999 in a city park in the US city of Baltimore.

The podcast explored whether Adnan Syed, who was found guilty of her murder, really committed the crime.

Serial logo
Image caption One year ago everybody you know (just about) was hooked on the weekly podcast, Serial

Each week the podcast focused on a different aspect of the case, from mobile phone records on the day Hae was murdered, to scenes from court.

Each episode featured long interviews with Syed, from jail, conducted by host Sarah Koenig, a journalist who also works on This American Life.

It became a global hit with a reported 68 million downloads across the 12 episodes.

It's expected the new series will follow the same format, featuring testimony from Bergdahl himself.

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