Dame Joan Collins has revealed the 68-year-old royal - who was thought to be the socialite's godfather - appeared visibly ''sad'' when she passed on her condolences to him at an event for his charity The Prince's Trust shortly after the model's passing.
She said: ''It was terrible, terrible news. A lot of people were broken up. Prince Charles, too. Shortly afterwards, I went to a thing for The Prince's Trust and said to him: 'I'm so sorry, Sir, about your friend Tara'. And he looked very sad. She was his godchild.''
The 83-year-old legendary actress was equally distraught when she found out that Tara had passed away at the age of just 45 because she remembers vividly how happy and healthy she looked when she attended the star's book launch just last year.
Speaking to The Sun newspaper, she said: ''I saw her [Tara] last year. She came to my book launch. She was full of life and talking about what she was going to be doing.
''She said: 'I've been off the radar because I haven't been well. I'm happy now I'm back'. It's very sad. She was quite young.''
It was initially thought Tara had passed away as a result of a relapse but tests carried out on her body last month revealed she had died from a perforated stomach ulcer.
Her sister Santa Montefiore said at the time: ''Today the Coroner's report states that Tara died of natural causes - a perforated ulcer. She did not have a brain tumour. (sic).''
The brunette beauty had told the world last year that she was convinced she had just ''weeks to live'' after she was told she had a brain tumour and was suffering from a rare auto-immune condition which saw abnormal antibodies attack the cells and tissues.
However, it's not known whether Tara had the tumour, which she said was on pituitary gland, removed prior to her death or whether she never actually had one.
Tara was laid to rest at the parish church in Dummer, Hampshire, just over a week ago.