The Missouri attorney general is investigating whether state officials violated the law by holding back a report on E. coli in a lake, a spokeswoman said.

The Lake of the Ozarks Watershed Alliance tested the lake in May and discovered unsafe levels of E. coli in the popular tourist lake, the St. Louis Post-Dispatch reported Saturday. The volunteers gave their report to the Department of Natural Resources but the agency did not release it until late June.

An agency spokeswoman told The Kansas City Star the report was held so it could be studied further and to avoid panicking tourists during vacation season.

Attorney General Chris Koster is looking into whether the environmental officials violated the state's "Sunshine Law" by delaying its release.

Although the levels were higher than allowed by the Environmental Protection Agency, state health records show no E. coli infections at the lake. However, a Sunrise Beach man said Friday he was hospitalized for three days in mid-May with an E. coli infection and that he swims in the lake every day.