His memories uncovered a secret jail - right next to an international airport

When investigators smashed through a hastily built wall, they uncovered a set of secret jail cells.

It turned out to be a freshly bricked-up doorway – an attempt to hide what lurked behind.

Inside, off a narrow hallway, were tiny rooms to the right and left. It was pitch-black.

The team may never have found this clandestine jail – a stone's throw from Dhaka's International Airport – without the recollections of Mir Ahmad Bin Quasem and others.

A critic of Bangladesh's ousted leader, he was held there for eight years.

He was blindfolded for much of his time in the prison, so he leaned on the sounds he could recall - and he distinctly remembered the sound of planes landing.

That was what helped lead investigators to the military base near the airport. Behind the main building on the compound, they found the smaller, heavily guarded, windowless structure made of brick and concrete where detainees were kept.

It was hidden in plain sight.

Rasel says he was approached by a group of men outside a mosque in Dhaka's old city last July, as anti-government protests raged. They said they were from law enforcement and he had to go with them.

The next minute, he was taken into a grey car, handcuffed, hooded and blindfolded. Forty minutes later, he was pulled out of the car, taken into a building and put in a room.

"After about half an hour, people started coming in one by one and asking questions. Who are you? What do you do?" Then the beatings started, he says.

"Being inside that place was terrifying. I felt like I would never get out."

Rasel now lives with his sister and her husband. Sitting on a dining chair in her flat in Dhaka, he describes his weeks in captivity in detail. He speaks with little emotion, seemingly detached from his experience.

He too believes his detention was politically motivated because he was a student leader with the rival Bangladesh Nationalist Party (BNP), of which his father was a senior member. His brother, who lived abroad, would frequently write social media posts critical of Hasina.

Rasel says there was no way of knowing where he was held. But after watching interim leader Muhammad Yunus visiting three detention centres earlier this year, he thinks he was kept in Agargaon district in Dhaka.

Tajul Islam believes the people held in these prisons are evidence of Awami League involvement. "All the people who were detained here were from different political identities and they just raised their voice against the previous regime, the government of that time, and that is why they were brought here."

To date they have issued 122 arrest warrants, but no one has yet been brought to justice.

Which is why victims like Iqbal Chowdhury, 71, believe their lives are still in danger. Chowdhury wants to leave Bangladesh. For years after he was released in 2019, he didn't leave his house, not even to go to the market. Chowdhury was warned by his captors never to speak of his detention.

"If you ever reveal where you were or what happened, and if you are taken again, no one will ever find or see you again. You will be vanished from this world," he says he was told.

Accused of writing propaganda against India and the Awami League, Chowdhury says that is why he was tortured.

"I was physically assaulted with an electric shock as well as being beaten. Now one of my fingers is heavily damaged by the electric shock. I lost my leg's strength, lost physical strength." He remembers the sound of others being physically tortured, grown men howling and crying in agony.

"I am still scared," says Chowdhury.

Rahmatullah, 23, is also terrified. "They took away a year and a half of my life. Those times won't ever be returned," he says. "They made me sleep in a place where a human being should not even be."

On 29 August 2023, he was taken from his home at midnight by RAB officers, some in uniform and others dressed in plain clothes. He was working as a cook in a neighbouring town while training to be an electrician.

After repeated interrogations, it became clear to Rahmatullah he was being forcibly detained for his anti-India and Islamic posts on social media. Using a pen and paper, he draws the layout of his cell, including the open drain he would use to relieve himself.

"Even thinking about that place in Dhaka makes me feel horrible. There was no space to lie down properly, so I had to sleep being curled up. I couldn't stretch my legs while lying down."