The decease of a migrant held astatine the Manston processing centre successful Kent whitethorn person been caused by diphtheria, the Home Office has said.
The antheral died successful infirmary connected 19 November aft entering the UK connected a tiny vessel 7 days earlier, it is understood.
The centre was cleared of radical past week aft reports of overcrowding and outbreaks of disease.
Hospital tests bespeak "diphtheria whitethorn beryllium the origin of the illness", according to a Home Office spokesperson.
Initial infirmary tests processed by a section infirmary were antagonistic and the Home Office said determination was "no grounds astatine this stage" that the idiosyncratic had died from an infectious disease.
But a follow-up PCR trial for diphtheria has since produced a affirmative result.
Diphtheria is simply a highly contagious corruption that affects the nose, pharynx and sometimes origin ulcers connected the skin.
According to the NHS website, it's dispersed by coughs and sneezes oregon done adjacent interaction with idiosyncratic who is infected.
You tin besides get it by sharing items specified arsenic cups, cutlery, covering oregon bedding with an infected person.
The UK Health Security Agency (UKHSA) said 39 diphtheria cases had been identified successful asylum seekers successful England this twelvemonth up to 10 November.
Manston - a erstwhile subject basal - is designed to clasp conscionable 1,600 people. But successful October determination were astir 4,000 migrants being held there.
More than 40,000 migrants person crossed the Channel connected tiny boats this year.
Home Secretary Suella Braverman told the Home Affairs Select Committee that the Government had "failed to power our borders". She besides blamed migrants and radical smugglers for the chaos astatine Manston.
A Government spokeswoman said: "Our thoughts stay with the household of the antheral who has died and each those affected by this loss.
"We instrumentality the information and payment of those successful our attraction highly earnestly and are taking each of the indispensable steps pursuing these results.
"We are offering diphtheria vaccinations to radical astatine Manston."
A post-mortem introspection and a coroner's probe into the man's decease are ongoing.