BBC journalist Martin Bashir is "seriously unwell" with complications from coronavirus, the corporation has said.
The 57-year-old, who made headlines across the world with his 1995 interview with Princess Diana, is currently BBC News religion editor.
"Everyone at the BBC is wishing him a full recovery," a spokeswoman said.
Mr Bashir is also known for interviews with pop star Michael Jackson and the suspects in the Stephen Lawrence case.
"We are sorry to say that Martin is seriously unwell with Covid-19 related complications," the BBC spokeswoman said.
"We'd ask that his privacy, and that of his family, is respected at this time."
Mr Bashir worked as a BBC news correspondent from 1987 to 1992, before joining the BBC's investigative programme Panorama.
Record audience figures
On that programme in 1995, he interviewed Diana, Princess of Wales, who admitted to having had an affair - and spoke of Prince Charles's relationship with Camilla Parker-Bowles, now Duchess of Cornwall.
"There were three of us in this marriage, so it was a bit crowded," she said, in a programme watched by one of the largest-ever audiences for the BBC.
The interview has seen renewed interest following a Channel 4 documentary examining the story behind Princess Diana's revelations, which was broadcast on Wednesday night.
Later, Mr Bashir worked for Tonight on ITV before moving to the US in 2004, where he hosted ABC's Nightline programme and worked as a news anchor on MSNBC.
He resigned from MSNBC in 2013 with an apology for calling former US vice-presidential candidate Sarah Palin a "world-class idiot".
In 2016, Mr Bashir rejoined the BBC as religious affairs correspondent. A former student of theology, he covers events in the UK and around the world affecting people of different faiths.