Shocking footage of foxes on a fur farm in Poland has revealed the appalling conditions in which the animals are kept.

The undercover video obtained by MailOnline shows the foxes cramped inside dark, dingy metal cages in western Poland.

One of the foxes has an eye missing and another has a rotting jaw while others are seen crouched, shivering in dark corners of the filthy cages, pacing up and down nervously.

It follows equally shocking evidence of 'monster foxes', bred on fur farms in Finland, living in deplorable conditions.

Footage from five farms across Ostrobothnia, western Finland, showed foxes with huge pelts and rolls of fat folded over their bodies in a bid to increase the amount of fur on their bodies.

Shocking footage of foxes on a fur farm in Poland has revealed the appalling conditions in which the animals are kept

The undercover video obtained by MailOnline shows the foxes cramped inside dark, dingy metal cages in western Poland

It follows equally shocking evidence of 'monster foxes', bred on fur farms in Finland (pictured), living in deplorable conditions

Poland is the world's third largest producer of fox fur behind Denmark and China, with nearly 800 farms spread across the country, according to Polish-based group Open Cages which carried out the investigation.

The largest of the farms can hold up to 200,000 animals.

'Most of the foxes, around 90 percent, are kept locked up in their cages for the 6 months of their lives,' Pawel Rawicki from Open Cages told MailOnline.

'The only time they are not in a cage is when they are taken from their mothers and moved to a different cage and when they are taken away to be skinned.

'Breeders live longer and in most cases this is worse as they have to endure the suffering for longer. On average, a breeder will be in a cage for between one and two years.'

Over the last couple of weeks Open Cages' investigators visited three farms in the Wielkopolska region of Poland, one exclusively for foxes, one for minks, and a mixed farm for foxes and racoons.

The farms hold between 500 to 4,000 animals each.

Poland is the world's third largest producer of fox fur behind Denmark and China, with nearly 800 farms spread across the country

Over the last couple of weeks Open Cages' investigators visited three farms in the Wielkopolska region of Poland

Pavel Rawicki described the conditions inside as being like 'a living hell'. He said: 'You can easily smell the animals from quite a distance, the smell of their waste, the rotting food.

'People living nearby complain all the time about it. They are filthy places. One of the ones we visited was flooded with a lot of dirt and mud everywhere.

'Another one seemed half-abandoned, I guess it probably isn't doing well financially It's deeply tragic and sad. You can easily say they places are like hell on earth.

'You can hear the animals biting the bars on the cages, trying to get out, and hear them running back and forth in the tiny space. It's very alarming.'

Around 100,00 foxes, nine million minks and 10,000 racoons are killed every year for fur in Poland. The animals are born in spring and killed in November and December.

Open Cages spokesman Pawel Rawicki told the MailOnline: 'Sometimes, because of the stress, mothers kill their cubs, sometimes the animals kill each other and eat the weaker ones. Mainly because of the size of the cages with too many in one cage.'

He added: 'Foxes, raccoon dogs and mink are carnivores that are not adapted to being confined in cages, hence the numerous acts of aggression, fighting and cannibalism.'

Earlier this year, Open Cages managed to rescue some foxes and in April they were placed into a new fox sanctuary at a zoo in the Polish city of Poznan. But thousands remain locked up with the certainty of death.

Around 100,00 foxes, nine million minks and 10,000 racoons are killed every year for fur in Poland

'You can hear the animals biting the bars on the cages, trying to get out,' Pawel Rawicki from Open Cages told MailOnline

A British film director who has been investigating fox farms in Poland for a documentary to be previewed next month in Poland said he was horrified at what he had discovered.

Connor M Jackson told MailOnline: 'In the Winter of 2016, myself and Open Cages conducted an undercover investigation into a small fox and raccoon dog farm, in Wielkopolska.

'It was November so the killing season had already begun, meaning less animals than usual. But even from down the road we could hear them crying and barking.

'Once inside we immediately saw faeces stacked high in piles, under each cage without fail: this came with a hot putrid stench.

'We saw foxes and raccoon dogs squeezed into small, metal, cold-looking cages: sometimes many in one cage. I could hear some animals urinating in their cages.

'We found many apathetic animals sitting unusually still, some were inquisitive and sniffing us.

'Not long after getting into the farm we found two animals showing classic symptoms of Stereotypy - a type of madness from confinement.

The largest of the farms in Poland are believed to hold up to 200,000 animals living in tiny cages

'One frantically scratching at its cage seemingly to dig a way out, another was running around in circles over and over.

'Its tongue was held out as it made this motion without rest, for the whole 30 minutes until we left.'

He added: 'Fur is untraceable because it goes from the farms to auction houses, so after these auctions it has no trace of its origin.

'However, due to Poland being the third biggest fur producer in the world: you can assume a lot of UK fur would come from Poland.'

It comes in the same week the Oikeutta eläimille (Animal Justice) group in Finland uncovered the devastating results of over-breeding.

It found how foxes were overfed a diet with a very high fat content so they grow as large as possible.

They said that in the wild, female foxes weigh around 3.5kg while a fox they photographed at the farm weighed more than 19kg.

The foxes look almost unrecognisable as they were fattened up for the fur trade

Shocking footage showed foxes struggling to move and with thick rolls of fur covering their eyelids, making them virtually unrecognisable as foxes.

Oikeutta eläimille said it is illegal in Finland to breed livestock in a way that causes animals to suffer.

It typically takes around 10 to 20 'normal' foxes to make a fur coat but the animals are also used to make hats, gilets and trims for jacket hoods.