The state of Oregon is keeping critical details about millions of dollars in business subsidies from the public, according to a report released Wednesday.

“Revealing Tax Subsidies 2013,” published by the Oregon State Public Interest Research Group, outlines the failure of most state agencies that offer economic development incentives to release timely information about subsidies, which are funded by Oregon taxpayers and expected to cost more than $665 million in the 2013-15 biennium.

OSPIRG monitored 18 corporate tax subsidy programs required by the Legislature to submit annual reports to the state. Those subsidies include property tax breaks for companies that set up in enterprise zones, tax breaks for out-of-state companies that move to Oregon, energy conservation subsidies and others.

The reports are supposed to be published by the end of each year on the Oregon Transparency Website, which was launched in 2009.

But OSPIRG found that just six of the 18 subsidy programs published any information on the website. Only one — a subsidy for film and TV production companies that spend more than $1 million in Oregon — provided enough information to evaluate whether the program was using funds effectively.

Some economic development officials have argued that such details are exempt from disclosure because they amount to “trade secrets” under Oregon law.

OSPIRG in its report argued that the public can’t gauge the effectiveness of these programs without more disclosure.

“The ability of the public to see how their government uses the public purse is fundamental to democracy,” wrote the report’s author, OSPIRG Consumer and Taxpayer Advocate Celeste Meiffren. “When public subsidies are given to private companies to advance goals related to economic growth, the public should see a timely and full accounting of the results of its investment.”

Paul Warner, the state’s Legislative Revenue Officer, said Wednesday that he hadn’t yet read the report. But he and other lawmakers would fully review it, likely after ongoing talks about the state budget wrap up.

“We have a definite interest throughout the Legislature in transparency,” Warner said.

The report also recommends that Gov. John Kitzhaber actively remind state agencies about transparency and their roles in handling public money.