A prisoner who had been transferred from a jail in Thailand and is being tested for coronavirus has been named as Mark John Rumble.
Thai authorities confirmed the identity of the 31-year-old, who was brought back to the UK on a flight two weeks ago.
He was taken to HMP Bullingdon in Oxfordshire, Sky News understands.
Prisoners at the Bicester jail are now being kept in isolation in their cells, with access also restricted to the wing of the complex where they are being held.
The prison has capacity for 1,114 inmates - including those on remand, those who have been sentenced, and young adults aged 18 to 21 - and remains operational, with Public Health England on site helping to manage the situation.
As Rumble and another prisoner were being tested, a British honeymooner who was removed from the Diamond Princess cruise ship over coronavirus fears has said his first test for the virus was negative.
Alan Steele wrote on Facebook: "Just received great news. My test showed negative to virus and have now been swabbed for second test. If that comes back negative I get released."
Meanwhile, the World Health Organisation (WHO) announced the illness would now be called COVID-19.
WHO director general Tedros Adhanom Ghebreyesus said the first vaccine could be ready in 18 months "so we have to do everything today using available weapons to fight this virus".
Other latest developments:
Eight people in the UK have been confirmed as having COVID-19, with the last four testing positive on Monday.
Health Secretary Matt Hancock announced on Tuesday that the government is launching a capital fund to support any urgent work the NHS needs to carry out to prevent the virus spreading, such as isolation facilities.
He said the NHS has been working hard to contact trace anybody infected patients have been around, and said that was how five people in the UK and five others in France, linked to Mr Walsh, were found.
Professor Paul Cosford, emeritus medical director of Public Health England (PHE), said "contact tracing" run by PHE was "working very well".
He added: "I should say that the people who are of concern are those who have had very close contact with somebody with coronavirus - face-to-face contact or within a two-metre range for 15 minutes or more."
PHE is now working to trace about a dozen people who were in contact with two doctors, including a Brighton GP, who were among the four new cases announced on Monday.
Two GP surgeries that had been closed due to COVID-19 have now re-opened.