Overcrowding is so severe at some US migrant detention facilities that adult detainees are held in cells where they each have less than 0.3 sq meters of space.

A report released this week showed photographs of detainees pressed against the outermost walls of cells, but to understand the extent of the overcrowding, the Guardian contacted a research agency called Forensic Architecture that is based at the University of London.

The researchers began with a photograph that was included in Tuesday’s report about conditions at the Rio Grande detention facility in Texas. The Office of the Inspector General (OIG) found that 88 adult men were being held in a cell with a maximum capacity of 41.

Photograph of 88 adult males held in a cell with a maximum capacity of 41. Photograph: Office of the Inspector General

Next, the researchers found additional photographs of the facilities.

A photograph of the empty cell in which immigrants are detained at Rio Grande. Photograph: US GAO

A photograph of the empty cell in which immigrants are detained at Rio Grande. Photograph: US GAO

As Nicholas Zembashi from Forensic Architecture explains, “We undertook an open-source research to find images of the holding cells at Fort Brown Station from multiple perspectives. These then allowed us to compare architectural features, such as tiles, with the US-Letter-sized papers on the holding cell’s windows and subsequently determine that the cell in the image, is triangular in layout. Its dimensions are between 270 - 320 sq ft (25-30 m2).”

With 88 men in the cell, that would leave about 0.28 sqe meters or 3 sq ft per person.

The conditions at the immigration detention facility contravene standards published by the American Correctional Association which are 25 sqe ft (2.32 m2) for multiple cell occupancy (the International Committee of the Red Cross maintains even more space is required for the dignity and safety of prisoners; 37 sq ft or 3.4 m2).

The extent of the overcrowding is visualised in the image below.