The Minnesota campaign finance agency disclosed on Tuesday that it found $26 million worth of data problems in its records late last year.

The data errors were woven through campaign records back to 2000, the Campaign Finance and Public Disclosure Board found. The agency said about 13 percent of all contributions from one campaign group to another had problems.

The agency’s analysis found an even greater dollar disparity in the campaign finance data than the Star Tribune found in November. That analysis, which first reported the errors, found at least $20 million of donations missing from data back to 2001. The board, which also included 2000 data, found an additional $6 million in problem records.

Since the Star Tribune’s report, the board has been under pressure to address the issue and fix the problems. Last month, the Legislature held a hearing to focus on the flaws and the board has discussed the issue at three consecutive meetings.

The agency’s analysis and the newspaper’s findings highlight the same root problem. In data long made public, one campaign organization frequently will report donations given to another Minnesota campaign, which does not in turn report receiving the donation. Equally problematic: Campaigns often report receiving a donation from a group to which the donor did not report giving.

The campaign watchdog has reduced the volume of the problems since November. By the end of 2013, it had fixed about $8 million worth of mismatched records. But it still had $18 million to go, according to board records from Dec. 27.

Many of the fixes stemmed from regular data checks the agency performs and the resolution of very large errors from 2002.

Those quick and massive fixes will not be the route of the future, as campaign regulators continue to work to make their records balance.

“Going forward we are going to have to be looking at smaller records,” Jeff Sigurdson, the campaign finance agency’s assistant executive director, said at a board meeting Tuesday.

“The good thing that’s come to light about this all is we do want this to be transparent, we do want this to be available to the public,” said former state Sen. Deanna Wiener, the board’s chairwoman.

In addition to its analysis of the problems, the agency has removed millions of dollars worth of donations from its website in cases when it found unreconciled data. Omitting those means that the agency now reports $18 million less cash flowing among campaigns than it previously had.

The agency also has added a disclaimer to its searchable online site, alerting the public that the online data may include errors.

On Tuesday the board approved a legislative proposal to require politicians and groups to work promptly with the agency to reconcile errors. Previously, agency staff members largely relied on good will from candidates and campaigns.

If approved by the Legislature and signed by the governor, the measure would fine uncooperative campaigns $25 a day, up to $1,000, for failing to comply. The board also will ask legislators to allow civil penalties of up to $3,000.