Roselane Driza, 37, of north London, told the Old Bailey she kept a homemade sex video of the two Asylum and Immigration Tribunal judges - one of whom was also her lover - in case anything happened to her.

"I did not have it to blackmail them. I had no reason to," she told the court.

"I ended thinking she could end up paying someone to kill me," she said of Judge J, who had fired her as a cleaner.

Driza worked over several years for both judges before being fired in 2004.

One is a man who can only be referred to as Judge I for legal reasons, and the other a woman described as Judge J.

Driza said the tape also showed Judge J taking cocaine, a claim the judge denies.

Prosecutors have already told the jury that Driza tried to blackmail Judge I into living rent-free in his home and accuse her of trying to extort 20,000 pounds from Judge J in exchange for not exposing them for employing her illegally and for not revealing details of their private lives.

The prosecution has also said that after the breakdown of Driza's relationship with Judge I - who had described her in emails as his "real chilli hot stuff" lover - she stole two of his homemade sex films.

They featured him having sex with two different women, one of whom was Judge J.

Driza, who told the jury last week she had stumbled across the videos while cleaning but had since destroyed them, also said on Monday that she had resisted pressure by her employer to have sex on video with him.

The defendant has admitted trying to sell her story to a newspaper but denies the theft and blackmail charges against her.