California is the only state in the country that has refused to reveal public spending records to a government watchdog, prompting threats of legal action.

OpenTheBooks.com, a nonprofit dedicated to government transparency, said the Golden State is the lone holdout since it began sending public record inquiries to state governments in 2013. Governments in 49 states have complied with requests for itemized accounts of taxpayer funds sent to vendors and public sector employees. California's state government, however, has so far failed to provide the details of the 49 million individual payments it makes each year using taxpayer dollars, saying it is unable to track and document its activities.

"Their excuse is that they can't locate the records—that their system doesn't allow the controller after she makes the payment to track the payment," OpenTheBooks.com founder Adam Andrzejewski told the Washington Free Beacon. "We are preparing to sue the State of California and force them to open their books."

The office of the California state controller Betty Yee did not respond to requests for comment.

OpenTheBooks.com has previously sued state governments to disclose the details of their spending, targeting both sides of the aisle from heavily Republican Wyoming to Democrat stronghold Illinois. The group has now set its sights on a legal battle in California to force the state to comply with its open record laws.

"They're just raising a massive red flag because, obviously, they're hiding everything," Andrzejewski said.

Yee has made fiscal stewardship a centerpiece of her tenure as the state controller. She claimed that the state identified $4.35 billion in waste, abuse, and mismanagement since she assumed office in 2015. Andrzejewski said such public pronouncements pale in comparison to how much money is spent each year by America's most populous state.

"The state spent about $1.5 trillion during this time," he said. "Does anyone except Betty Yee really believe that 99.97 percent of all state spending is proper? The controller is not even looking for waste."

OpenTheBooks.com is not the only taxpayer watchdog focusing on California's financial dysfunction. Transparent California, a government oversight group, has taken the state to court, alleging that the government pension system, CalPERS, has hindered attempts to discover fraud. CalPERS has refused requests to release information about disability and retirement payments that could help identify fraud in a program that is short $60 billion, according to Robert Fellner, executive director of Transparent California.

"CalPERS has their own disability fraud tip line saying, ‘We actually need the public's assistance to identify and detect [fraud],'" Fellner told the Free Beacon. "It seems really odd that they would refuse to disclose this one data point that's pretty important in distinguishing or helping to identify disability fraud."

The group initially sued the CalPERS system demanding access to the pension data in 2018. A California judge sided with the state in November, ruling that the request infringes on workers' privacy rights. Transparent California is in the process of filing an appeal.

Fellner said that the case could set a dangerous precedent for government transparency if the court's ruling is upheld because it could declare off-limits all public information that is even tangentially related to people's private information.

"The way the judge ruled and making this confidential is extremely dangerous," he said. "You can't say, ‘Well, medical records are confidential. Therefore, so is the pension type.'"

OpenTheBooks.com sees a similar risk if the state is able to thwart public records requests about state spending.

"It's their legal obligation," the group said in a release. "Taxpayers deserve to know how their money—to the tune of $320 Billion a year—is being spent."