HONOLULU >> It’s been months since same-sex marriage became legal in Hawaii, but taxpayers still don’t know how much money supporters or opponents spent to influence the decision.

Lobbyists are supposed disclose how much money they’re spending to influence lawmakers, but critics say the state disclosure system is among the weakest in the nation and prevents a timely and complete tally.

It could be that nothing improper took place, but “if you don’t have the information then how do you even know to have a concern?” asked Democratic state Sen. Les Ihara, who has introduced legislation he hopes will strengthen the system.

Ihara’s measures aim to close gaps that allowed more than 90 percent of nearly 200 registered individual lobbyists to report zero expenses over three reporting periods last year, according to reviews by The Associated Press.

According to the current law, lobbyists are required to list expenditures worth more than $25 toward one person in one day or $150 to one person over a reporting period, which is similar to disclosure rules that apply at the federal level.

But Ihara, the majority policy leader, said lobbyists in Hawaii operate under a longtime interpretation of the law by the state ethics commission that if the money they spend comes from an organization such as a business or advocacy group, they don’t have to report it in the disclosure system. The ethics panel’s position, Ihara said, holds that requiring that level of reporting would be duplicative. But “the ethics commission has misinterpreted the law,” he said.

Les Kondo, the commission’s executive director, declined to comment on the practice.

Lobbyist Scott Matsuura, a lobbyist who has reported zero expenditures said that he and his colleagues have been abiding by the rules the state has outlined. “For most of us, we’re following what we’ve been told to do,” he said.

The Center for Public Integrity, a nonprofit investigative journalism organization, gave Hawaii a D-minus for its lobbying disclosure practices on a 2012 report. The state’s system has not changed since that review.

The public should “know what gifts or entertainment that lobbyist provided to individual legislators,” said Gordon Witkin, the center’s managing editor.

Lobbyists must report expenditures each January, March and May. Critics say this reporting schedule creates another problem, one that doesn’t give taxpayers and government watchdogs timely information about the influence exerted on lawmakers.

“When it’s months later, people are going to forget,” Ihara said.

For instance, gay marriage, an issue that generated heated testimony from thousands of people and raucous rallies on both sides, passed with heavy support during a special session that ended Nov. 12, but based on reporting requirements, disclosures won’t be made until Friday. Even then, however, critics say, under the ethics panel’s position, taxpayers will likely learn little.

Ihara said government watchdog groups have suggested requiring more complete monthly reports during the regular session. In the rare event of a special session, Ihara suggests that reports be filed 10 days after the session adjourns.

Kondo, the ethics panel director, said changing when reports are due “would certainly add to the already full plate of the commission staff.”

It’s not clear whether Ihara’s overhauls will pass — they were introduced this month and haven’t received a hearing — but legislators ignored similar bills last year.

Neither Rep. Karl Rhoads nor Sen. Clayton Hee, both Democrats and chairmen of their chambers’ respective Judiciary committees, held hearings for a proposal to require more information from lobbyists.

At the time, Rhoads said lawmakers had more controversial matters to address. Hee said then that the proposal needed more research.

Rhoads, whose wife is a lobbyist, said Friday that he’s open to hearing a bill addressing disclosure rules, but added “I’m skeptical about whether it’s hard to put the pieces together. I think you can learn an awful lot by looking at the lobbyist filings.”

The problem is the system, not the lobbyists, said Janet Mason, legislative chair of the League of Women Voters of Hawaii.

“We recognize the lobbyists are very influential, but we don’t think we’re dealing with a cast of nefarious characters,” she said. However, she added, “the public has a right to understand who is influencing and shaping public policy.”