The collective hum of hundreds of sewing machine needles ploughing through fabric pierces the air as the prisoners get to work.

The factory floor is a sea of yellow uniforms worn by the 2,500 prisoners – and the thousands more they are stitching together.

At Centro Industrial prison in Santa Ana, the low-security jail where Kilmar Abrego Garcia, the El Salvadorian man mistakenly deported from the US, is being held, prisoners are referred to as “trusted inmates” and given jobs based on their skills in a bid to prepare them to reintegrate into society.

When The Telegraph visited the prison on Monday morning, there were just a handful of armed guards at the prison, a stark contrast to Cecot, the high-security prison Mr Abrego Garcia was originally sent to where bare-chested inmates with shaved heads are crammed into cells.

Away from the assembly line, “trusted inmates” in Centro Industrial are tasked with rearing cattle for dairy products, preparing food in the industrial kitchen or painting pictures for public offices.