Mona Dotcom has alleged her estranged husband attempted to wrest control of the family trust the day after she left him.
Mona Dotcom said changes were made to the family's Trust Me Trust "despite my protests", which placed control of the fortune in the hands of the internet entrepreneur.
"I began to worry about the Trust Me Trust's funds and Kim's actions," she said in legal papers filed in the United States.
The break-up last May began as a sideshow to the serious business of illegal spying and US efforts to extradite Dotcom, who is wanted in America on criminal copyright charges.
But court action by US authorities to seize the Dotcoms' fortune ahead of a claim by Hollywood and recording studios has seen the relationship meltdown become an integral part of the case, with Mona Dotcom claiming she is entitled to $23 million in the separation.
As details of the couple's relationship become public through court filings, and a magazine story of Mona Dotcom's relationship with a young South Auckland video gamer.
Mona Dotcom's latest affidavit details the breakdown of their relationship and the tussle for control of the Trust Me Trust.
She said the trust was set up in July 2012 by Dotcom "for the benefit of our family" and she was appointed the sole shareholder of the holding company, MD Corporate Trustee Ltd.
The couple split on May 12, 2014, and the day after, Dotcom exercised his power to appoint the trustee by removing MD Corporate Trustee Ltd and replacing it with Coatesville Trustee, of which he was sole shareholder and director, she said.
"I was concerned that Kim would utilise Coatesville Trustee to make distributions from the Trust Me Trust that were not in the interests of the beneficiaries."
She began legal proceedings to remove his authority over the trust - and his ability to appoint the controlling figure. She said they settled the dispute and she was again placed in control of the trust.
Mona Dotcom said the Trust Me Trust held shares in Mega, the cloudsharing business launched by Dotcom and his Megaupload co-accused a year after they were arrested. She said she was unsure of the value of the shares, which had been restrained as part of the US legal case.
Meanwhile, she claimed Dotcom had used $6 million which was jointly owned "to pay for his legal fees and legal expenses".
Mogul looks for true love online
The internet has given Kim Dotcom so much - now he's hoping it will bring him "new love".
The entrepreneur tweeted last week that he had been single for a year and wanted the internet to help him find someone.
He told the Weekend Herald: "I have been alone for a year and now I don't want to be alone anymore. I never go out. So the best way for me to meet someone new is the internet. I have received a lot of positive feedback. The hard part will be to find a genuine and compatible soul. It will take time."