CHARLOTTE, N.C. -- Interest groups from outside North Carolina have poured a record $20 million into the state before the general elections, helping fuel attack ads in the state's top races.

The Charlotte Observer reported Thursday that groups ranging from environmentalists to gun owners are spending heavily in North Carolina, on top of the millions of dollars being spent by the candidates.

According to the newspaper's analysis of public records, most of the outside money has gone to the U.S. Senate race between Republican incumbent Elizabeth Dole and Democratic challenger Kay Hagan. Money also has been heavily spent in the race for governor.

The biggest spender is the Democratic Senatorial Campaign Committee, which has spent more than $6.6 million in North Carolina, mostly to fund anti-Dole television ads.