Exclusive footage obtained by the Guardian of ballot papers pre-marked for Hamid Karzai that were seized by monitors. The ballots appear to be stamped with the monitors' seal and ready to cast. The monitors filmed then destroyed the papers to stop them being used

The shaky footage shows two election monitors inspecting a book of 100 ballot papers that are still stitched together, as they were intended to arrive at the polling station in rural Afghanistan. But something is wrong; instead of being pristine, ready for the voter to make his or her mark, each paper bears a large blue tick next to the name of one candidate: Hamid Karzai.

As the monitors flick through the pad, the back of the ballots clearly show the authorisation stamp of election monitors, validating them as votes ready to be put in the ballot box and counted.

"We found it the day after the elections," one of the monitors in the footage told me. "They were trying to put it in one of the [ballot] boxes but didn't have time, so we took it home and filmed it. If we had given it back to the election committee they would have used it again, so we burned it, but filmed it to protect ourselves if they come and threaten us."

The video footage is just part of a picture of widespread fraud in the Afghan election uncovered by the Guardian.

On Thursday, President Karzai told a news conference: "I believe firmly, firmly in the integrity of the election and the integrity of the Afghan people, and the integrity of the government in that process." But evidence given by a number of officials and voters tells a very different story, one in which the selling of votes to presidential candidates was common and the idea of the election being fair was laughable.

I met a different official outside a Kabul juice bar, where he sat on the kerb with a look of defeat on his face, clutching a glass of squeezed pomegranate and wrapped by the blue fumes of kebab stalls and passing cars.

He showed me a series of photographs taken inside a brown cardboard voting booth in a village in Paktiya province of Afghanistan. One shows a man marking a big pile of ballot papers in the name of Hamid Karzai. Another shows a pile of election ID cards spread in front of an unidentified man wearing black shoes. "This man brought 120 cards and he used each of them to vote three times," said the official.

He had intended to hand his photographs to his superiors, he said, but as election day unfolded it became obvious that his superiors were themselves taking part in the fraud. "I thought I would give the pictures to the election committee. But they were all working for Karzai." Fearing he had been spotted taking the pictures, he fled to Kabul.

"Everyone was cheating in my polling station. Only 10% voted, but they registered 100% turnout. One man brought five books of ballots, each containing 100 votes, and stuffed them in the boxes after the elections were over."

The election official came from the district of Ahmad Aba in Paktiya, an area of dusty hills framed by high, ragged mountains and typical Afghan hamlets with mud-walled compounds, cornfields and orchards.

I sat there with half a dozen men on an embankment in the shadow of willow and apple trees. They were waiting for the Ramadan fast to pass, fumbling with their plastic prayer beads. Boys sat in a bigger circle behind the men and behind them shoes, a prosthetic leg and flip-flops were stacked.

Haggling

As the men relaxed and smilingly described the election day, it became clear that what would constitute large-scale fraud in western context meant little more to them than the usual haggling over chicken or vegetables in a market.

"Election day was very good and very peaceful here," said one villager. "The security was very good. It was a like a feast day."

"Personally on polling day I put in 10 ballots," said another. "I took my voting card and the cards of the women in my family and went to the polling station. No one said anything to me. All the women's votes were cast in this way."

Behind the embankment, the women and girls stood in a stream, washing clothes. Another three were scrubbing the metal gate of a nearby compound, preparing for the end of Ramadan.

A man with a shiny black turban joined the circle. Told what we were discussing, he laughed. "On polling day the people who did the cheating were the officials," he said. "They worked for the candidates." His family had voted, he said, but the women hadn't gone to the polling station. Their ballots were sold to the candidates' representatives. "Only four old women cast their votes."

The vote had come down to a battle of budgets, with agents for both Karzai and his rival, Abdullah Abdullah, giving money in exchange for votes.

"The big tribal elders took lots of money from Karzai and Abdullah Abdullah. They were supposed to distribute it, but they didn't give much to us, only 1,000 Afghani ($20), or a mobile phone card. The elders took all the money."

The black turbaned man squinted mischievously. "Election day was a good day," he said. "We hope there is election every year." The men laughed.

In a nearby hamlet I met a fresh-faced election monitor who said he was 25 but looked younger. We squatted on the edge of a dusty field while he described how the fraud had worked in his village.

"It was all cheating on election day," he said. "Each candidate had his men cheating for him in the polling station and they all knew the others were cheating. Even I cheated," he said. "I didn't want to, but when I saw everyone cheating, I put 20 ballots in for Ashraf Ghani [a former finance minister], and then I called all my friends in other villages and we collected more ballots for him.

"In the beginning I thought of selling my 20 cards to Karzai or Abdullah, but then I said no, they have enough votes." He showed me three identical voting cards with his name and picture. "It was so easy to get those," he said.

"Karzai and Abdullah had their men in the polling station, but there was no one for [Ghani], so we cheated for him. He is a very educated man and with good strategy for Afghanistan. Also we are all from his tribe in this area. I tried to put my extra ballots in our polling station, but I had some enemies who tried to take my picture so I went to another polling station and no one asked to ink my finger or anything, they just said bring cards and put them in the box. It was a very happy day.

"Karzai's men were paying 1,000 Afghani per family and Abdullah's were paying 1,500 Afghani. But many people took money from Abdullah and voted for Karzai anyway."

The election monitor insisted it was a "democratic" area, meaning only that they were not hostile to government. They were educated and many worked in the government, but they had also worked in all previous governments.

Like many differences in Afghanistan, the cheating had run along ethnic lines. In the villages, where people were predominantly Pashtun, they had generally cheated for Karzai, but in the provincial capital, Gardez, the mostly Tajik people had cheated for Abdullah Abdullah.

Violations

I drove into Gardez to meet a third election monitor.

Shots rang out in the distance as we talked. The Taliban and Afghan security forces were fighting on the outskirts, but in the market life was normal. Street sellers shouted and trucks honked.

"I was offered $2,500 by Abdullah's team to work for them on election day, but I didn't," he said, describing a range of violations, from police ferrying voters so they could vote Karzai, to officials stuffing hundreds of ballots.

At Karzai's election headquarters in Gardez, he saw the head of a group of Pashtun tribes who he knew had taken money from Karzai's people. The village elders each took between $8,000 and $10,000, he said. "The election committee workers were very weak, so the representatives of each candidate took their 'own' boxes and started counting them."

There was a commotion, and a green police truck pulled up, parading the spoils of a rare victory: the dusty, bloody bodies of two dead Talibs.

We stood and watched as soldiers posed in front of them, their colleagues snapping pictures with mobile phones. A crowd gathered, and an Afghan officer in wraparound sunglasses began an impromptu victory speech.

We left them, and drove back to Kabul.