Starving children eat rats, families turn on each other and farmers kill their own livestock to survive. Smuggled film brings Mugabe nightmare to world's attention

A Guardian film smuggled out of Zimbabwe brings home the economic devastation and deprivation Robert Mugabe has wreaked upon his own people. With Morgan Tsvangirai, the opposition leader, preparing to take up the post of prime minister in a unity government, Sam Chakaipa, at considerable risk to himself and as an act of resistance, returned clandestinely to his village, 125 miles from Harare, to document the plight of his former neighbours.

The opposition activist has produced extraordinary footage of what Zimbabweans have to do in order to survive in a wrecked economy. As money is worthless – Zimbabwe is plagued by the world's highest inflation rate – the villagers are reduced to panning for gold in rivers. Instead of attending school, youngsters from the village scrabble knee-deep in muddy water or dig ever deeper holes in a desperate search for a few grains of gold.

These small supplies of the precious metal have thus become a crucial commodity Zimbabweans can trade for food; a loaf of bread is worth 0.1 grams. But only the young have the strength to dig and pan for gold; the village elders must go hungry, unless they have friends or relatives they can rely on. Some parents have been forced to feed rats to their children, and hunger has turned family members against each other.

In a particularly wrenching scene in the video, a 15-year-old girl with a swollen face describes tearfully how her grandmother beat her to drive her away as she was an extra mouth to feed. She says she has not eaten for three days.

"I'm hurting all over my body," she says. "There is nothing for me."

Chakaipa says: "I have never seen my people in such a desperate situation." Nothing is growing in the fields, and the farmers are killing their livestock, effectively destroying their livelihood.

Chakaipa, a member of the opposition Movement for Democratic Change (MDC), has suffered personally at the hands of Zanu-PF, Robert Mugabe's ruling party. He has been arrested and tortured, and his life was threatened when he wanted to stand as a councillor. His house has been burned down twice. As it is unsafe for him to stay in the village, Chakaipa has had to go into hiding in Harare.

His brother, also an MDC supporter, was not so lucky and was killed last year by Zanu-PF thugs. At one point in the film, in a mixture of reportage and personal testimony, Chakaipa stands in the ruins of his home telling us how the Mugabe government has destroyed his life.

It is too dangerous for the opposition, beaten into submission, to hold meetings or rallies, so Chakaipa chose to make this film as a personal act of defiance. He wants the world to see what Mugabe, who has been in power since 1980, has done to Zimbabwe: how he has reduced a once relatively prosperous country to ruin. Chakaipa does not hold out much hope for the unity government, in which the MDC leader, Morgan Tsvangirai, will be prime minister.

Zimbabwe's neighbours – particularly South Africa – put enormous pressure on Tsvangirai to accept this poisoned chalice, but many MDC supporters, including Chakaipa, say this was not what Zimbabweans voted for. He fears that if Tsvangirai works with Mugabe, "the suffering will continue".

Sam Chakaipa is an assumed name