Earnest noted that the investigation had been reported on in January. The Times first reported the federal investigation into Solis' activities at that time, citing sources familiar with the case.
"We weren't in a position to comment on that law enforcement investigation at that point, and I'm not in a position to comment on it today," he said.
Earnest said all administration members had been directed to follow the requirements of the Hatch Act, a federal law that prohibits executive branch federal employees from soliciting funds for political purposes.
"The clear guidance that every member of this administration has received is to follow the guidelines, both the spirit and letter of the Hatch Act," he said.
Earlier Wednesday, Rep.
Solis has not responded to a request for comment on the release of the recording. She has previously declined to comment in detail on questions about a related federal inquiry involving allegedly improper fundraising activity, but has said in statements that she does not believe she did anything wrong.
In the recording, the speaker identifies herself as Hilda Solis and says, "Just calling you off-the-record here. Wanted to ask you if you could, um, help us get folks organized to come to a fundraiser that we're doing for Organizing for America for Obama campaign on Friday at La Fonda at 6 p.m."
She goes on to say, "There are a lot of folks that we know that are coming, but wanted to ask you if you might help contribute or get other folks to help out."
The Times previously reported that the Office of Special Counsel, a federal agency that investigates possible administrative violations of fundraising rules by administration officials, opened an inquiry into allegations that Solis had solicited employees of the Labor Department to contribute to or help organize a Los Angeles fundraiser for the president.
The Office of Special Counsel closed its investigation when Solis stepped down from the Cabinet in January 2013. But the agency had referred the matter to the Department of Justice for possible criminal investigation.
Solis resigned her Cabinet post early last year and announced a bid for the Los Angeles County supervisorial seat being vacated by
Issa had subpoenaed the director of the White House Office of Political Strategy and Outreach, David Simas, to appear at Wednesday's hearing. Issa said the White House did not comply, saying Simas was immune from such a summons.