The man was taken to hospital on Friday after becoming unwell, says the Home Office.
Image source, PA MediaA migrant staying at the Manston processing centre in Kent has died, the Home Office has said.
The person was taken to hospital on Saturday after becoming unwell.
A Home Office spokesperson said: “We express our heartfelt condolences to all those affected.
“We take the safety of those in our care extremely seriously and are profoundly saddened by this event.
“A post-mortem examination will take place so it would not be appropriate to comment further at this time.”
The Home Office said there was “no evidence at this stage” that the person had died from an infectious disease.
They said: “We take the safety and welfare of those in our care extremely seriously and provide 24/7 health facilities with trained medical staff at Manston.”
Manston, which is a former military base, reopened as a migrant processing centre in February this year.
It was designed to hold migrants who had just arrived in the UK on small boats for 24 hours, and has a capacity 1,000 to 1,600 people.
After 24 hours at Manston, migrants are meant to be moved into the Home Office’s asylum accommodation system, which usually means staying in a hotel due to a lack of available accommodation.
But the centre has been the subject of controversy in recent weeks after it was revealed in October that there were around 4,000 migrants being held at Manston.
Some people were also being held for longer than 24 hours due to shortages in accommodation.
More than 40,000 migrants have arrived in Kent this year, with nearly 1,000 crossing the Channel on Saturday alone.