Michael Jackson has been accused of animal cruelty at his all-but abandoned Neverland ranch.

Animal rights activists have demanded an urgent probe into conditions at the sprawling estate.

They claim giraffes, elephants and other creatures are imprisoned in squalid and cramped surroundings.

Shocking photographs appear to reveal animals surrounded by their own faeces.

A giraffe seems to be standing in a pool of its own blood while a crocodile swims in a pool little wider than itself.

Elephants appear to be walking among their own excrement, with no sign of keepers.

A spokesman for animal rights' group PETA - People for the Ethical Treatment of Animals - called on Jackson to close down the zoo immediately.

Lisa Wathne said: 'These photos make it clear that the animals are being held in what can only be described as cruel conditions.

'They are abysmal and little more than holding cells. My message to Michael Jackson would be to close this place down and relocate the animals to an accredited zoo or sanctuary.'

PETA has sent a letter to the U.S. Department of Agriculture urging it to launch an investigation into conditions.

Employees at Neverland say the animals' food supply is fast running out.

One said: 'There is not much left. I don't know what will happen after that.'

Jackson, 47, may be forced to sell the 2,700-acre ranch in California's Santa Ynez Valley to pay off mounting debts.

He bought the estate - which once boasted a full zoo, fairground rides and a small scale steam railway - in 1988 for a reported $17million.

But since he was cleared of child sex charges in June, the once dream home has fallen into disrepair while Jackson and his children have been living in Bahrain as a guest of the country's Crown Prince .

Staff have been sacked or have simply quit after their wages were not paid, according to sources.

One insider said: 'Most of the staff have gone. Hundreds of people used to work here - now there are only ten or so.

'The electricity is only on in some parts of the house. Some rooms have been stripped of everything. Neverland is falling apart.' It emerged last week that Jackson is being sued by the vet employed to look after the exotic animals at his zoo.

Martin Dinnes, owner of Dinnes Memorial Veterinary Hospital, is claiming that the singer owes him £51,800 in unpaid bills.

Mr Dinnes's lawyer, Brenton Horner, said that his client had helped Jackson acquire the animals and continues to treat them regularly.

Last night, Brian Oxman, a lawyer for the singer, responded to the cruelty allegations by saying: 'Michael Jackson does not wish to comment on this story.'

A source close to the family insisted: 'The animals are being cared for perfectly well.'