A footage filmed five months prior to Princess Diana's death revealed that she caught Prince Charles engaging in phone sex with his mistress, Camilla, in the bathroom.

According to The Sun, an unnamed BBC cameraman was summoned by Diana, to Kensington Palace in March 1997.

The allegations were heard in a 12-hour footage, where Diana explained how she had caught Charles talking to Camilla, claiming she was the "raunchier of the two".

The anonymous cameraman had a diary of the recordings where 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 secret cameraman who made the 10-minute segments recording revealed that she said she “would do everything possible to make sure Charles never became King.”

“She wanted William to succeed to the throne when the Queen died. Diana clearly saw her role as the power behind William,” he continued.

“She had this somewhat romantic idea of being a king-maker, the mother behind the monarch.”

The tape also reveals that Diana said Charles was unperturbed by her affair with James Hewitt despite knowing, as it "gave him freedom".

A fee of £5,000 was paid to the cameraman for the recording session, and he bought two untraceable phones to avoid eavesdropping by the Secret Service.

While the exact location of the recordings are still unknown, The Sun reported on Sunday that the tapes—alongside tapes from the Settelen sessions—may have been discovered following a police raid on Paul Burrell's house, Diana's butler.

In the Settelen recordings, Diana claims Charles told her he “refused to be the only Prince of Wales who never had a mistress”.

Recorded in 1992 and 1993, the controversial tapes aired in America in 1995, with clips were she describes how Charles pestered her with chats 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.

Settelen was handed the tapes after a legal battle with the Spencers.