The BBC has unearthed new evidence the late Nigerian megachurch leader TB Joshua hid dead bodies and intimidated families, to cover up his role in the collapse of a building which killed at least 116 people at his church in 2014.

The collapse is one of the worst disasters to ever strike a place of worship in Africa.

The BBC's investigation is the first time insiders from TB Joshua's Synagogue Church of All Nations (Scoan) in Lagos have presented evidence of what caused the incident nearly 10 years ago, and of how the pastor allegedly orchestrated a cover-up.

It follows evidence uncovered by the BBC of widespread abuse and torture by the founder of one of the world's biggest Christian evangelical churches.

Two days after the collapse on 12 September 2014, TB Joshua publicly said it was linked to an aircraft that flew over the building used to house visiting pilgrims.

But an inquiry by a Lagos coroner agreed with emergency workers that structural failure had caused the guest house to collapse, and said it had been built without proper planning permission.

Eyewitnesses told the BBC that TB Joshua had been warned of serious structural problems prior to the disaster. They say the aeroplane explanation was a "lie".

"He knew the building was unstable," says Emmanuel, who spent more than a decade as a disciple of TB Joshua - a group of devout followers who lived in his church in Lagos.

Like most of the former disciples interviewed by the BBC, he opted to only use his first name.

He described the pastor receiving a report, hours before the collapse, that the building was "swaying" and "shaking".

Multiple witnesses say the visitors were not warned. Instead more than 200 of them were led into the building's dining room on the ground floor to eat their lunch - where they were seated when all six storeys of concrete descended on top of them.

Many were killed instantly, but more than 100 were trapped inside alive.

"I could hear people crying out: 'Help me, help me, help me,'" says Emmanuel, who was on the scene within minutes of the collapse.

"Their voices were fading and you could tell these people were dying off."

Others described horrifically injured victims, with missing eyes and limbs - splintered by the beams which came down on top of them.

"It was quite clear that that building was never built for the height that TB Joshua built it to," says Rae, from the UK, who spent 12 years living in the church as a disciple.

She says she was present when TB Joshua ordered his workers to construct additional floors: "The foundations weren't built to hold a building of that many storeys.

"He just kept kind of pushing and saying: 'I want it higher. It must go higher. It must go higher.'"

The church insiders who spoke to the BBC also say lives could potentially have been saved had TB Joshua responded promptly to the collapse itself. Instead, they say, he blocked emergency services from accessing the site for 24 hours - an allegation corroborated by news reports at the time.

During this crucial window for rescuing people and assisting the injured, the BBC's eyewitnesses say some church workers attempted to save lives in reckless and amateur ways. Without the use of mechanical equipment or medical training, they used tools from the church's maintenance department.

In one instance, a church worker allegedly used a chainsaw to amputate the leg of a man who was trapped under a fallen beam.

"He was screaming!" says Emmanuel, visibly shaken during his interview. He is not sure if the man survived.

"I saw a lot of things that really traumatised me… faces were crushed," says Michael, a disciple who was in his late teens at the time.

Eyewitness testimonies of the horrific aftermath have never been published before, with many church insiders sworn to secrecy, and the site of the collapse shielded from public view by a large wall.

Three sources, including Michael, say TB Joshua ordered his workers to move piles of dead bodies away from the building collapse site during the night, to hide them from the media and the authorities.

Two say they were asked to film this activity, and to deliver the tapes to TB Joshua in his office.

"We were recording them as they put them into body bags… loads and loads of people," says Michael.

Chloe, a former disciple of TB Joshua from the UK, also witnessed the aftermath of the collapse. She says she got into a bus and immediately noticed an awful smell.

The driver told her the vehicle was "full of dead bodies… and we're transporting them at night so that the press can't see them".

Multiple sources believe that the death toll was higher than the 116 figure given by the church, and cited friends and church workers who were inside at the time of the collapse who they say were not recorded in the official list of the dead.