A father and son who had "no regard for animal welfare or human health" have been warned they face jail.

Harold Gray and his son Michael were yesterday convicted of supplying meat to shops in Bradford and Keighley from a filthy, illegal slaughterhouse.

They allowed sheep to be killed in squalid conditions at their Upper Austby farm at Langbar, North Yorkshire, Harrogate magistrates heard.

The Grays denied running an unlicensed slaughterhouse but were convicted by District Judge Roy Anderson.

He was told Harold Gray had previous convictions for animal cruelty and failing to dispose of risk material properly.

He said: "These are serious matters. You must know that prison is an option."

The Court heard an open sewer ran through the slaughterhouse with human faeces present; a chopping block was covered in bird droppings; meat had maggots in it and meat hooks were rusty.

Conditions at the farm were exposed when animal welfare activists secretly filmed sheep being killed in 2003.

The video was handed to North Yorkshire Trading Standards and a raid on the farm took place.

As previously reported the conditions in which animals were being killed led Harold Gray, 62, his business partner, Michael Gray, 31, and slaughterman Sumaullah Patel, 41, to admit cruelty charges.

Patel, of Sunningdale Road, Bolton, admitted three offences of causing avoidable suffering to sheep. The Grays both pleaded guilty to aiding and abetting Patel and three offences of causing unnecessary suffering to sheep. They admitted 11 offences of contravening the post-BSE regulations, failing to dispose properly of high-risk material and breaching rules on cattle movements, passports and records.

Both Grays denied doing anything wrong, claiming Trading Standards had known of their activities for 15 years.

All three were bailed to appear at Harrogate Magistrates' Court on March 23.

After the case Graham Venn, head of North Yorkshire Trading Standards, said: "These two gentlemen have no regard for animal welfare and human health.

''They are only interested, it seems, in profit."