Tragic Pictures Inside Hotel Bathroom Where Whitney Houston's Body Found

Asked if the music industry does enough to look after vulnerable performers, he said: 'It's about the people you surround yourself with. She really got involved in bad situations and the wrong crowd of people who led her down the wrong road.'

And music mogul Simon Cowell said that before her death he had approached her to ask if she would consider becoming a judge on the next season of the U.S. X-Factor.

He also paid tribute to Ms Houston and said the warning signs that she ‘still had problems’ came after the singer made an erratic appearance on the X Factor in 2009. The performance was to promote a new album after seven years off the scene.

He said: ‘There are always moments in your life that are horrible to remember. The day John Lennon died, the day Elvis died. More recently Michael Jackson, last year Amy Winehouse and now Whitney.

'I know quite a few people who had been working with her over the years. We all knew Whitney had issues. I last met her when she came on the X Factor. You could see at the time there were still a few problems but she was a delight to work with on the day.'

The guest appearance on X Factor - her first UK TV appearance for 12 years - was billed as the start of her comeback but the worrying performance raised concerns for her well being and she suffered an embarrassing wardrobe malfunction when her dress straps snapped.

Miss Houston then embarked on her Nothing But Love World Tour tour in 2010, but the UK leg was beset by cancellations. She was forced to reschedule the first three dates in Manchester and Glasgow after picking up a respiratory infection. She finally played her first UK gig in 11 years at the Birmingham LG Arena.

The talent show judge told Sky: ‘She probably wasn’t all together but it was still Whitney Houston and you were in the presence of a legend and I will never forget that day.

'There are so few people like her in the world. They are a rarefied breed, these are true superstar legendary divas, but I say diva that in the nicest possible way. She had one of the best voices I heard in my life ever.’

And it was not just the music industry that felt the influence of Houston, with other celebrities expressing their condolences and thanks to the award-winning singer.