Aides to Republican lawmakers said Wednesday they are reviewing a 2003 trip to Ireland (search) to determine if a lobbyist paid for it — as congressional records indicate.

If the records are accurate, the trip by Sen. Gordon Smith (search) of Oregon, former Sen. Don Nickles (search) of Oklahoma and Reps. Howard Coble of North Carolina, Harold Rogers of Kentucky and Clay Shaw of Florida violated ethics rules that bar lobbying firms from paying for trips taken by members of Congress.

"If there was a problem with the paperwork we'll fix it promptly," said Chris Matthews, a spokesman for Smith.

"We are trying to obtain documentation of who paid so we can go back and review this with the ethics committee," said Ed McDonald, Coble's chief of staff.

The Hill, a newspaper that covers Capitol Hill, reported Wednesday that the five GOP lawmakers traveled to Ireland at the expense of a Washington lobbying firm, Kessler & Associates Business Services Inc.

The trip, a four-day international trade seminar at Ashford Castle in Ireland's County Mayo, took place in August 2003, the newspaper said.

Disclosure reports for the five lawmakers show that Kessler & Associates footed the $25,000 bill, even though congressional ethics guidelines bar lobbying firms from paying for lawmakers' travel.

Matthews and McDonald said Wednesday it was not clear whether the firm, headed by veteran lobbyist Richard Kessler, in fact paid for the trip, or whether it was paid for by its parent company.

Ethics guidelines allow companies, trade groups and nonprofit organizations — but not lobbyists or lobbying firms — to sponsor travel by members of Congress.

Coble's office listed Kessler Associates as the trip's sponsor on House disclosure forms, said McDonald, who was not on Coble's staff at the time the trip occurred.

But McDonald said Kessler told him earlier this week that the firm's parent company, Century Business Services Inc., a Cleveland-based accounting and consulting firm, had actually sponsored the trip.

A spokeswoman for Shaw, Gail Gitcho, said Shaw's office would likely amend his disclosure report to list Century Business Services as the sponsor.

"We are still looking into it," Gitcho said. "We are gathering further documentation."

A woman who answered the phone at Kessler's Capitol Hill office on Wednesday declined to comment.