Rep. Cliff Stearns (R-Fla.), the chairman of the House Energy and Commerce Subcommittee on Oversight and Investigations, today reiterated concerns about whether President Barack Obama’s long form birth certificate, released in April, is authentic.

Referring to an investigation by Maricopa County [Ariz.] Sheriff Joe Arpaio, Stearns said he is “looking at all the evidence.”

Arpaio, an iconoclastic sheriff in the Phoenix area who has gained a nationwide following for his hard-line stance on immigration, as well as making county jail inmates wear pink underwear and eat green bologna, earlier this month said a volunteer posse of his had evidence that the long form birth certificate is a forgery.

“Some of these people seem to have legitimate concerns. So, I don’t think it’s unreasonable just to see what they have to say,” Stearns said.

The comments followed remarks made Feb. 25 in Belleview, Fla., questioning whether the birth certificate Obama released is “legitimate.” Those remarks attracted criticism from Democrats.

Questions about Obama’s birthplace, and the documents proving he was born in Hawaii in 1961, became a grass-roots phenomenon on the right in the first years of his presidency, peaking with a campaign by Donald Trump for Obama to release a long form birth certificate with additional information from the documents his campaign released in 2008.

But since Obama released the long form birth certificate in April, those concerns had largely subsided, at least among most GOP officials.

Stearns, who has spearheaded such high-profile probes as his panel’s look at the Solyndra controversy, appears to be the most senior Republican to raise the issue since then.