The court ruled that 2Day FM radio station had broken the law by broadcasting two of its hosts impersonating Queen Elizabeth II and Prince Charles.
Saldanha, who had received the prank call, was found hanging in her nurse's accommodation at a London hospital days later.
Senior British Indian MP Keith Vaz, who has been the Saldanha family spokesperson since the incident in December 2012, called on the court to issue tough sentences in the case.
"Now that the prank call has been correctly deemed illegal, I hope the sentencing will take into consideration the severe harm that was caused by the broadcast and be sufficiently severe. I hope the judges throw the book at them," he said.
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Vaz, chair of the House of Commons Home Affairs Select Committee, said the family was still waiting for publication of the reports of the regulatory authorities in Australia, which will "help them get closure".
The call, made by DJs Mel Greig and Michael Christian, had featured the pair trying to get through to Kate Middleton while she was pregnant with Prince George in King Edward VII Hospital in London in December 2012.
Greig apologised for her role in the incident at Saldanha's inquest last year, and has spoken of her horror and disgust at the part she played in the prank.
In it, he wrote: "It is unbelievably sad and we both extend to and your family our deepest condolences.
"We were both very shocked to hear about Jacintha and have been thinking about her a lot recently. Many of the nurses spoke highly of her and I'm sure you know how great a nurse she was."
Saldanha is survived by her husband, Ben Barboza, and teenage children Lisha and Junal who are based in Bristol.