(Reuters) - The highest court in Kansas on Friday voided a voter-approved ordinance in Wichita to reduce punishments for possessing small amounts of marijuana.

By a 7-0 vote, the Kansas Supreme Court said Wichita ignored filing and disclosure rules that were mandated by state law, and meant to ensure that legislators and voters in the state’s most populous city understood the ordinance before a vote was taken.

These shortcomings meant voters were never “officially advised of the entirety” of what the ordinance meant, or how it would change existing law, Chief Justice Lawton Nuss wrote.

Approved by voters last April with a 54 percent majority, the ordinance set a maximum $50 fine for adults over 21 who were convicted for the first time of possessing no more than 32 grams (1.1 ounces) of marijuana, or related drug paraphernalia.

That conflicted with a state law classifying such an offense as a misdemeanor punishable by up to one year in prison and a $2,500 fine.

Kansas Attorney General Derek Schmidt had sought to void the Wichita ordinance on that basis and several others, including the basis for Friday’s decision.

The state supreme court had put the ordinance on hold while it reviewed its legality. Friday’s decision could set back efforts to ease marijuana laws in Kansas.

“We respect the court’s decision,” Wichita said in a statement. “The opinion provides clarity for all cities receiving such petitions. At this point there is no action for the city to take.”

Schmidt’s office did not immediately respond to requests for comment.

Wichita’s city council put the proposed ordinance up for a vote after a group called the Marijuana Reform Initiative filed petitions from thousands of people expressing support.

A spokesman, Esau Freeman, said the group was disappointed with the court’s decision. “It won’t hinder our efforts at the state level at all,” he added.