The Federal Communications Commission is investigating Republicans for Clean Air, a group backed by Texas entrepreneurs that began running ads last week touting George W. Bush's environmental record and criticizing John McCain's.

The ads ran in New York, Ohio, and California in advance of Tuesday's primaries. It initially was unclear who was behind the group or who paid for the ads until Sam Wyly, a Dallas software magnate and longtime Bush supporter, stepped forward Friday to take the credit.

McCain's campaign complained to the FCC, arguing that the ads should indicate they were actually funded by Wyly and his brother. At least one commissioner suggested she might agree.

Broadcasters had until the close of business Wednesday to submit information to the agency explaining what they did to uncover the group's true identity. The agency is trying to determine whether broadcasters conducted proper investigations before airing the ads, said Bobby Baker, an FCC attorney.

"We can't tell broadcasters to take something off the air,"he said.

"We could say that at least as facts exist in this situation, we have serious questions about whether you should add Sam Wyly to the identification."

Some stations have done just that, Baker added.

One commissioner, Gloria Tristani, issued a statement saying it appears the Republicans for Clean Air identification may be misleading because the ads are actually controlled and funded by the Wylys. She suggested the FCC should act quickly on 1 NEW3 McCain's complaint.

"Disclosure of a political advertisement's true sponsor, like disclosure of campaign contributions, help(s) ensure that the American public is fully informed about who is trying to influence their vote," Tristani wrote."But time is of the essence. It will do little good to find, after the presidential primaries are over, that these advertisements should no longer air unless the Wylys are identified as the true sponsors."

With McCain close to leaving the Republican race, FCC action in his favor may come too late to help him. But Wyly said last week that Republicans for Clean Air may run ads during the general election, so any FCC action may still be relevant.

McCain has also complained to the Federal Election Commission.