“It appears to me to be a pretty routine, straight-up audit, so I'm not really concerned,” said Joe Hunter, Cannon's chief of staff.

Hunter said the notice from the FEC, received last month, “indicated they're going to look at everything, which is fine. It's all there to look at.”

Hunter said that the campaign is working with the auditors and that Cannon's treasurer, state Sen. Curtis Bramble, has sent records to the FEC.

Larry Noble, a former general counsel with the FEC who now runs the Center for Responsive Politics, a campaign watchdog group, said the commission doesn't have the resources to do many audits, so they are “only done when there are enough problems to really warrant the FEC to look at them, so it's not a minor thing.”

The FEC has issued 44 audit reports on candidates for Congress in the 2000 and 2002 election cycles.

FEC spokesman Bob Biersack said he cannot comment on specific cases the commission may be investigating. However, he said that the commission cannot legally conduct random audits, so generally an audit can be triggered when the staff identifies questions relating to the "content or context" of the reports.

Cannon reported raising $640,259 in his successful 2004 re-election bid. He spent $634,195.

Hunter said Cannon's opponents, particularly those who oppose his immigration stand, have made complaints to the FEC and stirred up trouble, "so it certainly doesn't surprise me" that there would be an audit.

But Noble said the audits typically arise when the FEC analysts have reviewed the campaign's reports and found problems - and analysts identified numerous problems with Cannon's reports.

On 12 occasions in the 2004 campaign, the FEC analysts sent Bramble letters either raising questions about Cannon's fund raising and reporting or seeking additional information about how the campaign was spending money.

The FEC staff identified errors in the time frames covered by reports, missing information on contributions and disbursements, insufficient information regarding the purpose of various disbursements, and checks received after the party convention that were improperly credited toward convention expenses, raising the potential for contributions exceeding campaign finance limits.

Such inquires from the commission are not uncommon, but the frequency of problems with Cannon's reports may have raised red flags for FEC staff, prompting the audit.