LONDON – The BBC’s board of directors has approved the appointment of a retired senior judge to lead an independent investigation into the circumstances around a controversial 1995 TV interview with Princess Diana.Wednesday’s announcement came after Diana’s brother, Charles Spencer, made renewed claims this month that BBC journalist Martin Bashir used forged statements and false claims to convince the late royal to agree to the interview.The broadcaster’s director general, Tim Davie, said the BBC “is determined to get to the truth about these events.”Charles Spencer alleged that Bashir, 57, made false and defamatory claims about senior royals in order to gain his trust and access to his sister 25 years ago.