Princess Diana had overheard Prince Charles engaging in "phone sex" with his mistress Camilla while in the bathroom, a footage filmed five months prior to her death has revealed.The allegations were heard in 12 hours of footage filmed by a handpicked BBC cameraman, Mirror reported.According to The Sun, the cameraman, who has not been named, was summoned to Kensington Palace by Diana in March 1997.In seven sessions, she explained how she caught Charles talking to his mistress and even claimed Camilla was the “raunchier of the two,” giving examples to support this.The footage is not connected to the tapes made by speech coach Peter Settelen, which will be shown on Channnel 4.The cameraman kept a diary of the recordings in which he wrote: “She caught Charles and Camilla de flagrante after listening in to his phone calls.“She described how she came to listen to their phone calls. In one, Charles was sitting on the toilet seat when she caught him.”The recordings were made in 10-minute segments and the secret cameraman said she revealed she “would do everything possible to make sure Charles never became King.”He continued: “She wanted William to succeed to the throne when the Queen died. Diana clearly saw her role as the power behind William.“She had this somewhat romantic idea of being a king-maker, the mother behind the monarch.”It is also thought that Diana said on the tape that Charles did not care about her affair with James Hewitt, which he knew about, adding that it gave him freedom.The cameraman was paid £5,000 for the recording sessions and is said to have bought two untraceable phones for fear of the Secret Service eavesdropping.The exact whereabouts of the recordings is unknown but The Sun on Sunday revealed this morning that the tapes may have been recovered in a police raid on Diana’s butler Paul Burrell’s house along with the tapes from the Settelen sessions.The Settelen recordings, in which Diana claims Charles told her he “refused to be the only Prince of Wales who never had a mistress,” will be broadcast this evening in Diana: In Her Own Words.The controversial tapes were shot in 1992 and 1993 and then aired in America in 1995 but deemed too “hot” to show here.In the clips, she also describes how Charles “chatted her up like a bad rash,” when they first met.“He leapt on me and started kissing me and I thought, ‘Urgh,’ He was all over me for the rest of the evening, following me around like a puppy. Yes, I was flattered but I was very puzzled,” she said.After a legal battle with the Spencers, Setellen was given his tapes back but some were missing.When he asked police what else had been found in the raid, it is claimed he was shown an evidence log which had other tapes on it. When he asked to see them, he was allegedly told they were nothing to do with him.