SAN DIEGO -- Brent Wilkes, a top figure in the Randy "Duke" Cunningham bribery scandal, was fined $4,000 for making illegal donations to the 2000 mayoral candidacy of San Diego County Supervisor Ron Roberts, the San Diego Union-Tribune reported Tuesday.

Wilkes donated $500 through an employee of his Poway company, ADCS Inc., and her husband, the state Fair Political Practices found last week in handing down the maximum fine, The San Diego Union-Tribune reported.

According to Cunningham's plea agreement and lawyers, Wilkes was one of the businessmen who bribed the former congressman, paying off a $525,000 mortgage on a Rancho Santa Fe mansion and giving Cunningham more than $100,000 in cash. Although no charges have been filed against Wilkes, he could be indicted.

ADCS Inc. benefited from millions of dollars in contracts that Cunningham helped award through his position on a powerful House subcommittee.

Wilkes, who helped Cunningham and other Republicans, hosted a fundraiser for Roberts where he encouraged his employees to donate, the newspaper reported.

On May 31, 2000, one of Wilkes' employees, Amanda Ness, donated $250 to Roberts' campaign, as did her husband, the commission said in a report, according to the Union-Tribune.

About the same time, Wilkes gave Ness about $500 in cash, the newspaper reported.

Although Wilkes repeatedly said the $500 was not related to the donations, the report said "based on the totality of the evidence in this case, (Wilkes) was the true source of the two campaign contributions," the newspaper reported.