Tesco has suspended sales of chicken from an 'ethical' farm after an undercover investigation revealed shocking abuse of the birds.

The mistreatment at Brome Grange Farm, near Eye, in Suffolk, was captured on film by the Animal Justice Project.

The welfare group also found abuse was taking place at neighbouring Trees Farm.

Tesco has suspended sales of chicken from an 'ethical' farm after an undercover investigation revealed shocking abuse of the birds

The Animal Justice Project captured the abuse on film which shows a worker manhandling a bird

Both farms, run by Free Range Chicken Ltd, are signed up to the Red Tractor accreditation scheme. Trees Farm also belongs to the RSPCA Assured accreditation scheme.

The schemes are supposed to guarantee high welfare standards and their logos on food products are seen as an important guarantee for shoppers.

The film footage revealed lame and dying birds left to suffer for days. Baby chicks were kicked, thrown and killed, without being checked for vital signs.

One chick was left for more than eight hours to die. Another bird was left for a week with a deformed and twisted neck. Food and water was also contaminated with the birds' sodden bedding.

The film footage revealed lame and dying birds left to suffer for days even though the farms are signed up to schemes which are supposed to guarantee high welfare standards

One chick was left for more than eight hours to die while another bird was left for a week with a deformed and twisted neck

Workers are seen breaking birds' necks and throwing them convulsing on to the ground to die without checking if they were dead.

Professor Andrew Knight, of the centre for animal welfare at the University of Winchester, said the rough treatment of chicks and older birds risked causing significant injuries, adding: 'There is no excuse for such inhumane treatment of animals.'

A Tesco spokesman said: 'We have immediately suspended [Brome Grange] farm while we fully investigate and we will continue to engage with the appropriate authorities on welfare standards at the farm.'

The RSPCA confirmed Trees Farm had been suspended from the accreditation scheme, adding: 'We are shocked and disgusted. We are looking into these upsetting incidents.'

A Red Tractor spokesman said both farms had been 'suspended with immediate effect', adding: 'We take any allegations of breaches to these very seriously.'

Workers are seen in the footage breaking birds' necks and throwing them convulsing on to the ground to die without checking if they were dead

Both farms, run by Free Range Chicken Ltd, are signed up to the Red Tractor accreditation scheme but have since been suspended

It said the farms would only be reinstated if they could demonstrate that they had made all the necessary improvements to meet high animal welfare standards.

Free Range Chicken Ltd said: 'We have suspended supply from these two farms until we are satisfied that welfare standards are at the high levels we demand and members of the catching team involved have been dismissed.'

Animal Justice Project is launching a campaign called The Foul Truth which is designed to shine a light on the failure of schemes run by the RSPCA and Red Tractor to guarantee good animal welfare.

The campaign will involve a protest at the industry's Poultry Awards in London this week.