RENO, Nev. (AP) — Rupert Murdoch and four of his children on Monday went before a Nevada probate commissioner behind closed doors to an evidentiary hearing that could decide who controls Murdoch's media empire after his death.

The hearing scheduled to resume Tuesday and continue into next week comes after Murdoch, 93, moved last year to change the terms of his irrevocable family trust.

The New York Times reported, based on a sealed Washoe County court document, that it was part of a bid to ensure that his eldest son, Lachlan, remains in charge of his cadre of newspapers and television networks, including The Wall Street Journal and Fox News Channel.

The court has kept the hearings closed to the public and most documents sealed, largely rejecting requests for access by news organizations including The Associated Press.

The trust was originally set up to give equal control over Rupert Murdoch’s businesses to his four oldest children upon his death, according to the Times.

Murdoch stepped down as leader of both Fox News’ parent company and his News Corp. media holdings last fall. He is arguing that to preserve his businesses’ commercial value for all his heirs, the trust must be changed so Lachlan can ensure his newspapers and TV networks continue to have a conservative editorial outlook, the Times reported.

Lachlan succeeded his father as chairman of News Corp. in November. He's also executive officer at Fox Corp., home to conservative news network Fox News, the Fox broadcast and sports networks, and local TV stations. The media empire spans continents and helped to shape modern American politics.

Rupert Murdoch's bid to change the trust has pitted him against his other three children named as beneficiaries: James, Elisabeth and Prudence, and they have united to stop their father from revising the trust, according to the Times.

Irrevocable trusts are typically used to limit estate taxes, among other reasons, and can’t be changed without permission from the beneficiaries or via a court order.

Nevada Probate Commissioner Edmund J. Gorman of the Second Judicial District Court in Reno ruled this summer that Rupert Murdoch could amend the trust if he can show that he is acting in good faith and for the sole benefit of his heirs, the Times reported.

The court's ruling notes that Murdoch sought to give Lachlan permanent and exclusive control over his companies because the mogul was worried that a lack of consensus among his children could affect the strategic direction at his companies, including potentially leading to a change in editorial policy and content, according to the Times report.