The broadcast of a BBC TV investigation into Martin Bashir's 1995 interview with Princess Diana will be delayed.
The broadcaster said the probe, which was due to air as a Panorama programme, has been postponed due to a "significant duty of care issue".
It had been due to go out on BBC One on Monday but will now be held.
A new broadcast date has not yet been confirmed.
He has been seriously ill with the after-effects of COVID-19.
In a message to staff, the BBC's deputy director of news Jonathan Munro said: "He let us know of his decision last month, just before being readmitted to hospital for another surgical procedure on his heart.
"Although he underwent major surgery toward the end of last year, he is facing some ongoing issues and has decided to focus on his health.
"We wish him a complete and speedy recovery."
Bashir interviewed the Princess of Wales while he was working as a reporter for the Panorama programme in the 1990s.
An investigation by Lord Dyson into how Bashir landed his 1995 interview has concluded and a BBC spokesman has said the findings would be published "very soon".
The former master of the rolls and head of civil justice was asked to examine what led up to the programme, which famously featured Diana saying: "Well, there were three of us in this marriage, so it was a bit crowded."
Late last year, after it was announced, her son Prince William welcomed the launch of the probe, saying it "should help establish the truth behind the actions" that led to his mother taking part.
His brother, Prince Harry, is also said to have supported the inquiry.
The investigation was ordered after Diana's brother Earl Spencer claimed Mr Bashir showed him fake financial documents relating to members of staff in the Royal household and told outlandish and untrue stories about the Royal Family in order to gain access to the princess.
Lord Dyson has been considering the extent to which the actions Bashir took influenced Diana's decision to give an interview and whether they were appropriate and also whether the BBC took adequate steps afterwards.