San Francisco Supervisor John Avalos failed to provide records to account for more than half the $656,000 he spent during his unsuccessful 2011 run for mayor, according to a city Ethics Commission audit.

Two-thirds of the money in his arsenal — $461,479 — came from public financing, raising questions about just how tightly the city monitors the spending of taxpayer dollars doled out to mayoral candidates under the city’s generous campaign financing law.

Voters first approved public financing for Board of Supervisors races in 2002, but it wasn’t used in the mayor’s race until 2011, when Avalos and several others challenged interim Mayor Ed Lee for the job. The program, which was promoted by the city’s progressive community, was intended to help grassroots candidates who otherwise might not be able to compete with better-known politicians.

But when it came to Avalos, at least, no one was minding the store.

The newly completed audit of his 2011 campaign found that Avalos’ committee “failed to maintain complete campaign records” for more than $391,000 in spending, or 60 percent of the total.

According to auditors who searched bank records, that included $631 paid for Web services to his then-wife, Karen Zapata, and $21,984 to his City Hall aide and campaign consultant, Raquel Redondiez, with whom he later confessed to having an affair.

The report also found that Avalos failed to keep complete records for $26,506 in campaign contributions, or 11 percent of what he raised from private donors.

In a June 4 letter to the Ethics Commission, Avalos said he realized “that the lack of documents is unacceptable.” But he said he had run a “very grassroots” campaign and that his “high level of reliance on volunteers, particularly for the treasury effort, made it difficult to manage” his finances.

“If I were ever to run for public office again,” Avalos said, “I will never structure my campaign staff and treasury operation in the same way.”

Avalos, by the way, didn’t spend every last dime he got from the city. Along with his letter to the Ethics Commission, he enclosed a check for $46,966 that was still sitting in a bank account — begging the question of why it took four years to return the unspent funds.

Ethics Commission executive John St. Croix said the audit findings will be turned over to his investigators and that Avalos will probably be fined.

Blame game: Ross Mirkarimi is standing squarely in the middle of all the political fallout from the Pier 14 killing of a 32-year-old woman, allegedly by a Mexican citizen here without documentation whom the San Francisco sheriff had let go.

And the timing couldn’t be worse for him, coming just as he tries to fire up his November re-election campaign.

But then, in the end, all the terrible PR is unlikely to make a difference on election day.

“He showed up at the race with four flat tires and a smoking engine” is how one political consultant put it.

The consensus is that Mirkarimi was already well beaten down by his misdemeanor conviction in a domestic-violence case involving his wife, the stairwell death at San Francisco General Hospital of a missing patient whom his deputies didn’t try too hard to find, and allegations — as yet unsubstantiated — that deputies arranged and gambled on fights between prisoners.

In fact, as far back as December, polling conducted by Mayor Ed Lee’s political team showed Mirkarimi trailing his only challenger, former interim Sheriff Vicki Hennessy, 41 percent to 29 percent.

Political analyst David Latterman says Mirkarimi’s political troubles were evident even in his 2011 victory when he defeated two moderate candidates — former Police Officers Association President Chris Cunnie and Sheriff’s Capt. Paul Miyamoto — with just 38 percent of first-pick votes.

It was a sign that Mirkarimi hasn’t been able to increase his support outside his progressive base, Latterman said.

Mirkarimi is in full damage-control mode now that the national spotlight is on him in the Kathryn Steinle slaying. But “truthfully,” Latterman said, “I don’t see a scenario where he can win.”