The Law Commission wants trust law changed to close a loophole used to hide assets in relationship breakups.
Between 300,000 and 500,000 trusts are currently being used to cover the family home, by charities and businesses and by Maori wishing to hold land collectively.
The commission has released a lengthy review recommending several major changes to the legislation covering trusts.
Law Commission President Sir Grant Hammond says the current law is outdated and difficult to understand.
One of the proposed changes would stop one party hiding property in a trust from another during the breakup of a de-facto relationship or civil union.
Sir Grant says the new law would allow courts to include a trust's assets in a separation settlement.
