Updated at 5:55 p.m. with response from Koster's campaign:

WASHINGTON -- The Woodinville millionaire who has bankrolled many of Tim Eyman's initiatives has given $6,000 to Republican John Koster's race for the 1st congressional district -- $1,000 more than allowed by federal campaign-finance rules.

Michael Dunmire, a retired investor and a long-time Eyman patron, made two $2,500 contributions to Koster's campaign in March. Trouble is, Dunmire also gave $1,000 to Koster last October. Individuals can give federal candidates $2,500 for primary election and $2,500 for general election, for a total of $5,000 per election cycle.

Koster's first-quarter fundraising report to the Federal Election Commission listed $1,200 in refunds. His campaign did not immediately respond to question about whether that included Dunmire's cash. Larry Stickney, Koster's campaign manager, said the excess donation is being reattributed to Dunmire's wife, Phyllis.

Koster, a Snohomish County councilmember, is the lone Republican candidate running to succeed Democrat Jay Inslee, who resigned in March to campaign full time for governor. Five Democrats and one independent also are running for Inslee's old seat.

Over the years, Dunmire has poured more than million dollars to Eyman's various initiatives. They included attempts to make it harder to raise taxes by requiring a 2/3 vote by the Legislature, limiting motor vehicle-registration fees to $30 and opening high-occupancy vehicle lanes to all traffic at "off-peak" hours.

Koster also received big financial backing from several conservative causes during the quarter. Citizens United Political Victory Fund, a political-action committee working to elect conservatives to Congress, gave $5,000.

The Republican National Coalition for Life gave $2,500. Koster opposes abortions under any circumstances, including incest and rape.