Despite a global investigation Megrahi’s conviction, and the failed appeals that followed, remain tainted- for some- by doubt and conspiracy theory.

After almost four decades, a new Lockerbie trial. Abu Agila Masud is due to go on trial in August. He denies any involvement and says a video confession he made in 2011 was forced.

Will the new trial finally put an end to it all?

Myles Bonnar revisits relatives of the victims and investigators, as new evidence challenges long held beliefs.

Lockerbie is produced by Caitlin Smith

Secret documents are recovered from the wreckage of Libyan intelligence agency.

Myles Bonnar is given access to copies of secret Libyan files which raise fresh questions about Megrahi and his alleged co-conspirators.

These documents have been dubbed the Senussi Files, after Abdullah Senussi – head of intelligence in Libya and Colonel Gaddafi’s brother-in-law.

The files were found in Tripoli, in the rubble of the Libyan intelligence agency, the JSO (or ESO) destroyed by Nato bombs following the 2011 Arab Spring uprising.

If verified, it links Megrahi, and others, to the Pan Am explosion, and raises new questions about the case.

Lockerbie is produced by Caitlin Smith

Secret agent or fantasist?

Jim Swire first met David BenAryeah at a gathering of the Lockerbie relatives in 1989. BenAryeah soon began passing him secret files from classified sources. So where did he get this information from and who was BenAryeah really?

It’s not just BenAryeah who emerged as a mysterious figure in this case, there’s another mysterious character Myles wants to find out more about.

Was Abdul Majid Giaka, aka Puzzle Piece, a double agent or a fantasist?

Myles manages to get hold of secret cables between Giaka and his CIA handler which sheds fresh light on what Giaka really knew.

Lockerbie is produced by Caitlin Smith

A grieving father is convinced the police investigation into Lockerbie got it wrong.

Myles Bonnar speaks with Jim Swire, whose daughter Flora died in the explosion. He tells Myles he believes the real culprit is Iran.

Jim has always been outspoken about his theories. He claims his rising profile attracted unwanted attention from intelligence agencies, both in Britain and abroad. But what did they want with him?

Jim tells Myles about David BenAryeah – a supporter of the Lockerbie group who Jim believed was a member of Israeli intelligence agency, Mossad. But Myles knows him as someone very different.

Jim Swire’s not the only one who has doubts about who bombed the plane and why. The Lockerbie case has long been at the centre of a complex web of conspiracy. Myles speaks with a member of Abdelbaset al-Megrahi’s appeal team who tell him what they believe really happened in the months leading up to the Pan Am explosion.

Lockerbie is produced by Caitlin Smith

In 1988, Dumfries and Galloway police is the smallest force in the UK: only 310 officers. Now they’re dealing with the world’s biggest crime scene.

Detectives from all over Scotland are bussed into Lockerbie overnight. Within days, American intelligence agents make an appearance. They hole up in Lockerbie Academy, each claiming a classroom.

Scottish police are determined to recover every single piece of evidence from the 845-mile crime scene. They bag everything that looks like plane debris before sending it off for forensic evaluation.

The investigation rolls on for two years, spanning Germany, Sweden, the UK, and Malta, a small Mediterranean island between Sicily and Libya. That’s when they make a series of breakthroughs.

Myles Bonnar speaks with investigators in Scotland and in the FBI about a Libyan double agent, dubbed Puzzle Piece. Could he unlock the whole investigation?

Lockerbie is produced by Caitlin Smith

Myles Bonnar pieces together the original police investigation.

He goes back to the night of the explosion; tracking down three sources, each with unique insight into how the police investigation unfolded.

From the very early days it’s clear confusion and conspiracy are taking hold.

Rumours circulate. Why are American special agents on board the flight? Was the plane used to smuggle drugs? Who are those mysterious figures in the woods in Lockerbie?

The police investigation narrows in on a Palestinian militant group. But are they the real culprits?

Lockerbie is produced by Caitlin Smith

One of the world’s longest running conspiracies. Who was really behind the Lockerbie bombing?

On 21 December 1988, a plane explodes over Lockerbie, Scotland, killing 270 people. A Libyan man, Abdelbaset al Megrahi, is convicted.

Despite a global investigation, Megrahi’s conviction, and the failed appeals that followed, are still tainted- for some- with doubt and conspiracy theory. Myles Bonnar wants to find out why.

Now, almost four decades on; fresh evidence and a new trial. The alleged bomb maker Abu Agila Masud is in custody, with a trial expected to begin any day. He denies any involvement in the Lockerbie bombing.

Journalist Myles Bonnar (Dead Man Running, Shiny Bob) picks apart the original investigation and finds himself in a world full of militant groups, top secret files and grieving families who will never give up on the pursuit of the truth.

Intrigue: 'Jaw-dropping', 'gripping', 'bingeable,' 'thrilling' - dramatic true stories and investigations that reveal how the world really works.

Lockerbie is produced by Caitlin Smith

The search for a convicted people smuggler who put money in the UK planning for retirement.

This investigation stems from a tip-off: a convicted smuggler once dubbed the most successful in history, is currently living in the UK and running a string of businesses here. Could it be true?

Sue and Rob go on the hunt for Twana Jamal – a smuggler who had so many aliases he had to write them on his baseball cap to remind himself which he was using. In court, prosecutors said he and his gang were making £4 million a year and they believed he was funnelling his money into UK businesses: car washes and mini-markets.

The search for Twana Jamal starts in the north of England, where migrants report seeing Twana driving a BMW and exuding an air of wealth. They remember how feared he was in the Calais camp: it was migrants there who reported him to police. His gang was the first to industrialise the lorry crossings, which featured so heavily in 2016 as thousands waited to reach Britain.

After a smuggling conviction and five-year prison sentence in France, Twana Jamal entered the UK and is believed to have given a different alias to the Home Office. Sue and Rob track him down to an English village, where he’s running a string of stores selling vapes, sweets and alcohol. Over several days they watch his movements to find out more about his life here. When the moment is right, they plan to confront him.

The series is researched and recorded by Sue Mitchell and Rob Lawrie.

Can Sue and Rob find a smuggler from the past who everyone thought had disappeared?

Listen to the final episode, Return of the King, on Wednesday 1 July, first on BBC Sounds.

A late night phone call: have Sue and Rob finally unmasked the people-smuggling king pin?

A journalist and an ex-soldier search for the identity of a people smuggler believed to be responsible for thousands of illegal crossings to the UK by small boats and lorries.

They start with a false name: Kardo Ranya. A man who has evaded arrest for several years by keeping his real identity a closely guarded secret. It makes it near impossible for law enforcement agencies to issue and international arrest warrant.

Sue and Rob know what he looks like from social media posts advertising his crossings and lifestyle. Their search takes them across Europe and to the Middle East, where they discover a network of powerful smugglers operating from a town in Northern Iraq.

It’s two years since Sue and Rob located a gang leader in their podcast Intrigue: To Catch a Scorpion and the illegal business of migrant journeys is more dangerous and ruthless than before.

Their investigation reveals the inner mechanics of the smuggling trade and shows in close focus the people who currently control it as they search for a kingpin behind dangerous crossings to the UK by boat and lorry.

A secret meeting, a missing person and a worried family. Who is the man connecting them?

The series is recorded and presented by Sue Mitchell

It’s produced by Joel Moors

Original music is by Mom Tudie and sound design and mix is by Tom Brignell

The Executive Producer is Joe Kent and the Commissioning Executive is Tracy Williams.

The Assistant Commissioner in Speech Digital is Will Drysdale

The Commissioning Editor is Dan Clarke