His murder trial captivated millions 15 years after it took place thanks to the popularity of Sarah Koenig's compelling podcast Serial.

Now Adnan Syed's hearing for post-conviction relief is well underway, and Serial has released a miniseries to keep listeners updated on developments.

His legal team are presenting new evidence at the three-day hearing in the hopes of securing him a new trial – including testimony from a witness potentially providing Syed with an alibi, as well as a document that calls an important part of the prosecution's evidence into question.

Syed was convicted in 2000 of the 1999 killing of his ex-girlfriend, 18-year-old Hae Min Lee, and sentenced to life in prison.

But the first day of the hearing heard from Asia McClain (now known as Asia Chapman), a fellow high school student who said she was with Syed, now 35, in a library on the day Lee was murdered. At the time, she says she was not called to testify or contacted by anyone from Syed's legal team.

His current legal team say his original trial attourney, Maria Cristina Gutierrez, was not fit to represent him as her physical and mental health was deterioating due to illness. Gutierrez passed away in 2004.

Koenig has taken time out from the second series of Serial to recap the court proceedings with producer Dana Chivvis. Of Chapman's evidence, she said: “There just like a lot of drama in the room when she was testifying […] She was very sure of herself and what she remembered.

“She came off really well for the defence.”

Of Syed's demeanour, Koenig said: “He just became a stone.”

The second main issue covered in the hearing was how mobile phone data was used to determine location in the original trial, placing Syed in Leakin Park where Lee's body was found. Justin Brown, from Syed’s legal team, says the data was misinterpreted.

The second day of the trial involved cross-examination of Chapman and testimony from an expert in cellphone forensics, Gerald Grant, who said the prosecution had not followed “instructions” on how to interpret the data.

A cover letter, which can be viewed on the Serial website, was sent by service provider AT&T stating, “Outgoing calls only are reliable for location status. Any incoming calls will NOT be considered reliable information.” Therefore, Brown says, the data that placed Syed in the park “should not have been admissible.” The original expert called in the case also signed an affadavit confirming that had he seen the cover letter, it would have "affected" his testimony.

Serial was a year in the making and hooked listeners from its release in October 2014, now boasting more than 100 million downloads.

Syed's brother Yusef has previously said of the podcast, “My brother was broken and alone. Then came Serial.”

This is the first time Syed’s team has had the opportunity to bring this evidence to court. As the hearing continues, Lee's family released a statement saying: “We believe justice was done when Adnan was convicted in 2000, and we look forward to bringing this chapter to an end so we can celebrate the memory of Hae instead of celebrating the man who killed her.”

Images: Rex Features / serialpodcast.org