Updated

A House committee chairman subpoenaed the Environmental Protection Agency on Friday seeking documents reviewed by the agency's administrator before he blocked a California tailpipe emissions law.

More than 16 other states were also blocked from implementing the first-in-the-nation greenhouse gas emissions controls when the EPA rejected California's waiver request in December.

In the wake of the controversial decision by EPA Administrator Stephen L. Johnson there have been indications he overruled EPA staff who recommended granting the waiver. Congressional investigators have released excerpts of an internal presentation made to Johnson that said California had a compelling need for the waiver, and that EPA was likely to lose in court if sued over denying it.

The EPA has refused to release that presentation publicly although congressional aides have reviewed it in private with agency staff present. The subpoena issued Friday by Rep. Henry Waxman, D-Calif., seeks an unredacted version of the presentation. Waxman chairs the House Government Reform and Oversight Committee.

EPA spokesman Jonathan Shradar contended congressional investigators had already seen the documents in question and said the agency had concerns about releasing them publicly because of ongoing litigation. California and other states have sued EPA over its decision to deny the waiver.

"What they've subpoenaed is to get control of documents that they have seen every word of. They know what it says," Shradar said. "I'm not going to imply that they would turn them over to those currently in litigation, but that is a concern."

When EPA denied California's waiver request in December, it said Congress' new fuel efficiency law was a better way to go because it set a national standard. California contends that its own law, which would have forced automakers to cut emissions of carbon dioxide and other greenhouse gases by 30 percent in new cars and light trucks by 2016, is stronger and takes effect more quickly than the new federal law.

The federal law would raise fuel economy standards nationwide to an average of 35 miles per gallon by 2020 while California says its law would result in standards of 36.8 mpg four years earlier, an analysis EPA disputes.

Twelve other states -- Connecticut, Maine, Maryland, Massachusetts, New Jersey, New Mexico, New York, Oregon, Pennsylvania, Rhode Island, Vermont and Washington -- have adopted California's tailpipe emissions laws. The governors of Arizona, Colorado, Florida and Utah have said they also plan to adopt them, and the rules were also under consideration elsewhere.