Before officials could sign off on the vote tally at Moscow polling station No. 81 in December's parliamentary poll, the local election commission chief had disappeared with the ballots, they said.
The election officials waited for her until almost 1:00 a.m., then gave up and went home. A security guard later told one of them he had seen Klavdia Titova, the head of the commission, climb out of a first-storey window.
When she reappeared the next day, an extra 322 votes had been added to the count of Prime Minister Vladimir Putin's United Russia party, court documents show. One official said his signature had been forged on the protocol.
The court denied an appeal by the opposition Communist party against the results, and, at the trial, Titova declined to comment to Reuters about the allegations.
Such reports have prompted tens of thousands of Russians to sign up as vote monitors for Sunday's presidential election to guard against a repeat of alleged irregularities that marred December's poll.
The fraud allegations have spawned a civil awakening and sparked the biggest opposition protests since Putin rose to power 12 years ago, although he is still all but certain to win the election.
It had never even entered my head before that an ordinary person could be a vote monitor. But after the December election I heard from friends who'd been observers and were upset by the falsifications that I could also try to do something, said Natasha Vostrikova, a 28-year-old translator at an IT company.
She was one of more than 100 people who gave up their Sunday to sit through a four-hour, powerpoint lecture on election law, one of dozens of training sessions organised by independent vote-monitoring groups.
There has never been so much talk of politics ... now everyone is not just talking but taking action, she said.
Many volunteers say they have no links to any political party. Independent groups are helping them register as monitors and sending them to polling stations which they say delivered suspiciously high results for United Russia in December.
The Kremlin has denied there was widespread fraud in December's election and dismissed opposition calls for a rerun.
Putin has said he wants Sunday's poll to be free and fair, and ordered 182,000 web cameras to be set up at the 91,000 voting stations across the vast country.
But his opponents have dismissed the 13-billion-rouble ($446-million) project as a sham and say they still fear fraud, complaining that what they regard as even the most blatant cases of ballot-stuffing have gone unpunished by the state.
I am going to be a vote observer, said Yevgeniya Chirikova, one of the opposition protest organisers. If we can prove that there is falsification ... then there will be a very strong reaction (from the people).
'NEVER BEEN ANYTHING LIKE IT'
The vote-monitoring groups say they have enough volunteers to send four or five people to all Moscow polling stations.
That means also deploying monitors in state institutions such as hospitals, homes for the elderly and prisons. United Russia scored particularly high tallies in such institutions in December.
Overall, about 30,000 volunteers have signed up to new online services that help them register as monitors, including one launched by anti-corruption blogger Alexei Navalny. Many more have registered directly with presidential candidates.
Suddenly having a civic stance has become trendy, said Georgy Alburov, who runs Navalny's RosVybory website. A huge number of people have started waking up.
Communist party candidate Gennady Zyuganov's campaign team said it was astonished at the number and enthusiasm of volunteers, 50 of whom have offered to go to Chechnya, where United Russia won 99 percent of the votes in December, despite the risk of violence in the volatile North Caucasus region.
Never has there been anything like this, Communist deputy Kazbek Taysayev said. The Moscow protests aren't just hot air. Everyone is fed up.
An aide to billionaire candidate Mikhail Prokhorov said 30,000 volunteers had approached his campaign team. About 65,000 have applied to register as observers from Putin's camp.
Many of the protesters at rallies in the past few weeks have been relatively wealthy, educated voters, but volunteer monitors at the training come from a variety of backgrounds.
It's not just a middle-class protest. At my work everyone hates Putin, said Yuri Zerkalov, 52, a car mechanic who signed up after attending a protest for the first time in his life.
Volunteers are taught that obtaining a copy of the end-of-day vote tallies is the best way to prevent cheating.
The handwritten protocols were key to proving fraud in the December 4 election where they differed from official results.
The independent Citizen Observers group said United Russia won about 26 percent of votes at Moscow polling stations where its observers registered no violations. Official results put the party's score at more than 46 percent in the capital.
Independent groups say catching fraud on election day is their only chance of ensuring a fair vote because seeking redress in court has been almost impossible.
Not every citizen who comes across fraud is ready to risk their career and personal life to fight the system, facing colossal pressure from state agencies, said Grigory Melkonyants, deputy head of independent monitor group Golos.
If they do get to court, it's almost futile.
Golos says Russians courts have thrown out all but two of 2,000 cases brought by observers since the December election.
GOING TO TRIAL
In a three-day trial in Moscow's Presensky district, a judge heard evidence of a litany of alleged violations at polling station No. 81, in Moscow's central House of Architecture.
A lawyer representing the Communist Party said the voter list was missing pages, officials were filmed ticking votes for United Russia in neatly folded packets of ballots, and election observers were expelled.
Natalia Ushlyakova, a Communist member of the election commission, was thrown out of the polling station by the local commission chief.
She said: 'If we count everything up well, they'll give us a nice bonus', Ushlyakova told Reuters. I guess she didn't like my answer.
In court, three people testified that a count of the ballots at 10.30 p.m. on voting day had placed United Russia third with 18.68 percent of the votes.
That tally was very similar to final results at the nearby polling station No. 80, where international monitors took photographs of the protocol to check against final results.
Vyacheslav Sokolov, an official with the district election commission, said he was on duty when local election commission chief Titova came to file the results at 12.45 p.m. the day after the election.
The final tally gave Putin's party 35.81 percent of the vote and took turnout from 53.22 percent to 89.44 percent, he said.
Titova said she never again wanted to work as an election official, adding: It's too hard. I'm taking tranquilizers.
According to her tally, 44 percent of voters cast their ballots in the last two hours of voting.
In closing arguments, lawyer Andrei Strogyi estimated it would have been physically impossible for 649 people to vote in that time with just four officials keeping the books.
They would have had to check the voter lists, write down passport details, get a signature and hand out the ballot to every voter in 44 seconds! he said.
The state prosecutor, who looked bored and drew doodles of flowers on her notepad during trial, advised the judge to dismiss the case. She said there was no reason to believe testimony that signatures were forged on the final protocol.
We have three kinds of law in Russia: civil, criminal and phone-call law, Strogyi said. If someone called her and told her what the decision should be, there is nothing we can do.
Judge Marina Tsyvkina threw out the case. The court later said in a statement it had reason to doubt the objectivity of election commission members with links to opposition parties.
It's like something out of (Franz) Kafka, said Maria Gavrilova, a vote monitor with the liberal group Yabloko, likening the situation to the surreal world of mad bureaucracy portrayed by the German-language author.
(Additional reporting by Maria Tsvetkova and Thomas Grove; Editing by Timothy Heritage and Louise Ireland)