Ombudsman Deborah Glass will evaluate whether the state government-owned company is acting in the best interests of its vulnerable clients.

The State Trustees acts as an administrator for people who are unable to manage their financial and legal affairs due to disability, illness or injury.

The company administers the financial and legal affairs of about 11,000 people, according to its most recent annual report.

Assets under State Trustees management were valued at more than $1 billion.

Ms Glass said the investigation was prompted by a ‘sustained increase’ in complaints to her office about State Trustees.

She said complaints about State Trustees rose by 37 per cent in the year to June 30, 2017, and had remained at the same high level since.

The ombudsman said an increasing number of complaints this year had warranted enquiries and file inspections.

“While we have been helping to resolve individual complaints about State Trustees, I have identified possible systemic issues that warrant a deeper examination,” Ms Glass said.

“People have complained that State Trustees did not consult them about decisions or take their wishes into account,” she said.

“There have been complaints that State Trustees did not pay bills or other expenses in a timely way. Others have said communication with State Trustees is difficult.

“Many of the people who rely on State Trustees are vulnerable, and I want to ensure their rights are respected and protected.”

State Trustees has an office in Ballarat.