MINNEAPOLIS  — The state of Minnesota isn’t making much effort to return unclaimed money to more than 50,000 rightful owners, people who include a U.S. senator, state commissioner and rock star.

The state Department of Commerce is holding onto $606 million in unclaimed assets. The stash includes funds from dormant bank accounts and safe-deposit boxes, as well as untouched death benefits and stock shares.

Most of the money ends up in the state’s general fund, although officials are obligated to return it if the owners are found.

Some of the owners should be easy to find. U.S. Sen. Amy Klobuchar, state Human Services Commissioner Lucinda Jesson and even rock star Prince are among those owed money.

So why can’t the Department of Commerce find them? Mainly because it’s not trying.

“We don’t, as a matter of normal course, go through a list of people that we have and try to find them,” said Emily Johnson Piper, the department’s deputy commissioner. “Presumably, people have already tried to find these people and they can’t.”

She said the state no longer notifies people but mail but it does try to inform them through publicity about unclaimed property and through the website missingmoney.com.

Some people say the state needs to do more. William Palmer, an attorney in Sacramento, Calif., who successfully sued that state in 2001 for failing to directly notify owners through mail and newspaper listings said Minnesota is improperly taking unclaimed property to help support its budget.

“What Minnesota is doing is a feel-good dog and pony show,” Palmer said. “There’s a fundamental constitutional requirement that you notify people before you touch their property.”

Johnson Piper said she wouldn’t comment on someone else’s legal opinion.

The agency provided the newspaper a copy of its database, current through 2011, listing the 57,000 people and companies who are owed money. The amounts range from $763,671 owed to a company called Hark & Co., to a single penny.

Klobuchar said she didn’t know the database listed her as being owed “over $100.” Jesson said she was “pleasantly surprised” to learn she was owed money, and a spokesman for Prince said he wasn’t aware the singer was in the database.

Experts say there are a number of reasons why property goes unclaimed. Heirs may not be aware of all of their loved ones’ assets, and life-insurance companies might not be able to find every beneficiary.