From Erika Bolstad in Washington D.C. --

It's taking longer than they thought it would to prepare Joe Miller personal financial disclosure information, said the Republican Senate candidate's campaign spokesman, Randy DeSoto.

Last week when the news broke that he hadn't yet turned in the paperwork, Miller told Fox News' Greta Van Susteren that the forms would be in "by the end of the week."

But the process has proved more time-consuming than they thought it would be, DeSoto said. Miller's accountant is currently reviewing his information.

"It's a very detailed report, so it's going to take a little while," DeSoto said. "It's just longer than anticipated."

All senators must file the forms each year. Candidates also are required to file them, and Miller's was due in April after he received more than $5,000 in campaign contributions. The forms detail investments, personal wealth and potential conflicts of interest.

Both of Miller's opponents, Sen. Lisa Murkowski and Democrat Scott McAdams, have filed their disclosure forms.

The Miller campaign's failure to turn in the disclosure forms wasn't intentional, DeSoto said. The campaign simply wasn't aware it needed to file them, he said. There is a $200 penalty for filing even one month past the due date. Failing to file the disclosure forms entirely can result in a fine of up to $50,000.