Bashir makes fly-on-the-wall documentary on Michael Jackson

Martin Bashir, the interviewer who coaxed a Panorama confessional from Diana, Princess of Wales, has spent the past eight months with the reclusive pop superstar Michael Jackson, making a fly-on-the-wall documentary.

Producers are promising fascinating insights into one of the most bizarre psyches to be found in the music industry and beyond, to be shown on ITV1.

The interviewer was with "Wacko Jacko" in Berlin when he notoriously dangled his new son from a hotel balcony two months ago. Mr Bashir was given "unprecedented and exclusive access" to the singer for the 90-minute profile, to be broadcast next month as a Tonight with Trevor McDonald special, the programme maker Granada said.

Jeff Anderson, Granada's controller of current affairs, said: "We have made this film entirely on our own terms. No money has been paid and no areas of the singer's career or personal life have been off- limits."

The programme is said to be a landmark film that gives a "fascinating personal insight into the mind of one of the world's biggest stars". Mr Bashir talks to the star in a series of interviews and goes behind the scenes at 44-year-old Jackson's Neverland ranch in California, which has its own fairground and zoo, on the first public tour of the site.

James Goldston, editor of Tonight, said: "The film is an extraordinary insight into the life of one of the most famous and controversial figures in the world.

"We have been filming with Michael Jackson throughout one of the most turbulent periods in his life. The results are utterly compelling. Viewers will not believe what they are seeing."