Sen. Richard Blumenthal has joined the ranks of self-funded candidates–those who use their own money for all or a substantial portion of their campaign treasury–albeit unintentionally, according to his latest campaign finance report.

Blumenthal lent his 2010 Senate campaign slightly more than $2.5 million, of some $8 million spent. He was forced to reclassify most of that as a contribution, however, by a federal law that requires repayment of candidate loans within 20 days of the election. Only $250,000 is exempt from the law, and is still on the campaign’s books as a debt.

“Quite honestly, there were efforts to raise money during that [20-day] period but it wasn’t enough to pay the loan off,” said Michael Cacace, Blumenthal’s campaign chairman in the 2010 contest.

Asked if Blumenthal realized that was a potential outcome, he said, “We knew what the law was and we were hopeful that we would raise the money to repay him.” He said Blumenthal will try to raise donations to repay himself the rest of the loan–the $250,000 that he’s allowed to carry over–in the next several months.

Blumenthal’s staff said he was unavailable Thursday.

Connecticut’s 2010 Senate campaign drew national attention over the self-funding issue, but not because of Blumenthal’s loan. Republican candidate Linda McMahon, co-founder of the WWE wrestling entertainment empire, poured $50 million of her own cash into the race, making it the most expensive Senate contest in the nation last year.

Even as McMahon pumped her own millions into the race, Connecticut Republicans raised questions about Blumenthal’s loans because the total amount he put up was more than his reported net worth. The total value of Blumenthal’s assets, according to his financial disclosure form, was between $599,000 to $1.36 million.

Blumenthal’s wife Cynthia, a member of the wealthy Malkin family, reported assets of between $55 million to $107 million. But she was limited, like any other individual donor, to giving her husband only $4,800 for the election.

Republicans raised questions about whether Blumenthal had lied on his financial disclosure forms or was somehow illegally funding his campaign–an assertion Blumenthal’s aides sharply dismissed.

They noted that the financial disclosure forms don’t take into account certain assets, such as a candidate’s home. And Maura Downes, Blumenthal’s campaign spokeswoman, later said he had borrowed against the value of his house.

Cacace elaborated on that for the first time Thursday, saying Blumenthal transferred his interest in the Greenwich house that he and Cynthia own to his wife. She then paid him the value of that share, which he pumped into the campaign.

“He transferred his interest in the marital home to his wife, who paid him his share of the house,” Cacace said. That allowed him to make the loan.

“It in point of fact was very much the lion’s share of his net worth,” Cacace said.