The BBC fell short of its high standards for integrity over how it persuaded Princess Diana to give the broadcaster an interview in 1995 and the journalist involved, Martin Bashir, was guilty of deceitful behaviour, a report concluded on Thursday.
The inquiry by a former senior judge concluded that Bashir had shown fake bank statements to persuade Diana's brother Charles Spencer to introduce his sister to him, reports Reuters.
"While the BBC cannot turn back the clock after a quarter of a century, we can make a full and unconditional apology. The BBC offers that today," BBC Director-General, Tim Davie, said.
Bashir responded in a statement Thursday that it was "saddening" the controversy had "been allowed to overshadow the princess' brave decision to tell her story," reports the CNN citing PA Media news agency.
The report, written by former judge Lord Dyson, found that Bashir had shown fake bank statements to Diana's brother Charles Spencer, which "deceived and induced him to arrange a meeting with Princess Diana."
"By gaining access to Princess Diana in this way, Bashir was able to persuade her to agree to give the interview," the report notes, adding that this behavior was in breach of BBC guidelines.
The 1995 interview was a seismic moment in British public life.
During the event, Diana told Bashir that there were "three of us" in her marriage to Charles, referring to Camilla Parker Bowles, whom the heir to the throne would later marry.
Buckingham Palace was blindsided by the interview and thrown into crisis by Diana's comments, which cast a rare light on the inner workings of the royal family.