Princess Diana's "indomitable spirit" will be showcased in the upcoming 'Diana: In Her Own Words' documentary.

The late royal - who tragically passed away in 1997 after being involved in a fatal car crash in Paris, France, aged 36 - will have private recordings broadcast on UK network Channel 4 on Sunday (06.08.17) when the documentary airs, and whilst the decision to show the clips has come under heavy criticism, her former aide Patrick Jephson has defended the documentary.

Speaking to the Daily Mirror newspaper, Patrick - who worked for the Princess between 1988 and 1996 - said: "At a time when, to their great credit, both her children are encouraging us to remember their mother in a positive light, this film is well-timed, well-made and well-intentioned.

"It's her irreverent, spontaneous and indomitable spirit that comes through loud and clear, despite the difficulties."

The private tapes were recorded between 1992 and 1993 by her voice coach Peter Settelen during a number of meetings in Kensington Palace, and have broadcasters Channel 4 have been criticised for "exploiting" the late Princess.

Royal author Penny Junor - who has written studies on Diana's ex-husband Prince Charles and their sons Prince William and Prince Harry - recently has condemned the release of the tapes as "deeply hurtful" to the royal family.

She said: "This is just another way of exploiting Diana. It's not what Charles would want and it's clearly not what the boys would want. It will be deeply hurtful to them.

"It seems to me a very bad idea to broadcast these tapes, especially at this difficult time for the family."

'Diana: In Her Own Words' will air in the UK on Channel 4 at 8pm on Sunday (06.08.17).