Spy: Power couple's messy break-up

Charlie and Ellie Aitken's wedding split has set Australian gossip magazines alight.

The marriage split of the step-daughter of one of Auckland's uber Rich Listers has lit up the gossip pages on the other side of the Tasman.

Sydney-based Ellie Aitken, 42, is the daughter of the very private Australian-born Celia Wyborn, wife of Viaduct Harbour Holdings' Mark Wyborn.

She has split from high-rolling funds manager husband Charlie, 48 — with the Australian press reporting he left Aitken for her best friend, Hollie Nasser, whose own husband, financier Christopher, was in business with Charlie.

Both couples have been described as the toast of Sydney society, with the women sharing their glamorous lifestyles and red-carpet moments on social media.

The Aitkens have been married for 20 years with two children and have often holidayed in New Zealand, mostly at the Wyborn's clifftop compound in the Bay of Islands.

Aitken has had an accomplished career as a lawyer and director and co-founded Aitken Investment Management with her husband.

Ellie Aitken and Julie Bishop, the former deputy leader of Australia's Liberal Party.

Her high-profile friends include former deputy leader of the Liberal Party Julie Bishop and Hollywood star Russell Crowe, with whom she went to an Oscars party in Los Angeles in 2016.

The Aitken break-up has been a talking point in well-heeled social circles in New Zealand over the summer break.

"It's no secret that the past few weeks have been an incredibly difficult time for me personally while dealing with a very hurtful private situation," Aitken wrote on Instagram.

"I had attempted to put on a brave face and tried to manage my feelings and well-being despite the fact that I have not had any control over the reasons for my sorrow.

"Unfortunately, I was pushed to my limit over the weekend and as a result, I made a painful matter worse by sharing my private thoughts on social media.

"The truth is that despite the support of friends and family I have not coped well with the deeply hurtful lies, gossip and innuendo that has surrounded the breakdown of my relationship. It is a situation that I honestly never expected to endure, let alone so publicly ... I now need to take time out to focus solely on me and my children."

Before Christmas, the Sydney Morning Herald reported Aitken had taken her two children for a month's escape in Aspen Colorado, a place where the family enjoyed previous holidays together. Her husband stayed in Sydney and moved back into their North Bondi home.