It is understood the star quietly contacted £550-an-hour Fiona Shackleton — Sir Paul McCartney’s legal expert in his £24million split from Heather Mills.
In June of that year, The Sun contacted representatives for Isla and Sacha regarding this, but they denied it.
But on Friday, the couple confirmed they had split last year — months after The Sun first approached them.
Baroness Shackleton, who also negotiated the then Prince Charles’ divorce to Princess Diana, advised the couple to go down an “amicable route”.
Insiders suggest the pair, who have three children, could go to war over Sacha’s estimated £40million fortune.
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Earlier tonight, a source said: “Isla has known for some time the marriage was over, and after some difficult conversations with Sacha, made the decision to consult a divorce lawyer.
“This was back in early summer, 2022.
“Fiona Shackleton was recommended by mutual contacts, and Isla was put in touch with an associate at the office.
“It was also suggested she seek out a lawyer in the US, where the couple have a home.
“Fiona is an incredible lawyer, and utterly fearsome in both reputation and ability.
“It was suggested they keep things as amicably as possible for the sake of the children.
“However, with Fiona on board, no stone will be left unturned if things did turn nasty — which neither of them want.”
The Sun also understands Borat actor Sacha, 52, has consulted with Laura Wasser, who represented Johnny Depp in his split from Amber Heard and worked on Angelina Jolie’s divorce from Brad Pitt.
The couple, who dated from 2001, announced their split on Friday, saying their 13-year marriage ended last year.
Ex-Home and Away star Isla, 48, has previously spoken about taking career breaks to raise their children and wanted to be around for them.
The Sun told over the weekend how Rebel Wilson’s sexual harassment claims against Sacha were the “catalyst” for the divorce announcement, according to sources.
In her autobiography, Rebel Rising, the actress made claims against the actor — which he strongly denies.
It is understood tensions in Isla and Sacha’s marriage started last year when they started looking for a house in London, with Sacha keen to move back home to Britain instead of LA and Perth.