West Midlands Police said the victim, aged in his 30s, is in a stable condition in hospital following the "shocking attack" which took place shortly after 9.20am last Tuesday.

His bedding was set alight and then piled on top of him near the intersection of Hockley Hill and Boulton Middleway, the force said.

It has released an image of a man who officers want to speak to who was riding on an electric scooter in the area at the time.

A police statement appealing for witnesses and information said: "We know this image isn't very clear, and we are working to find further CCTV opportunities, but we hope that this image may prompt someone to come forward with information.

"The man is described as white, 5ft 5in, and wearing a white vest, white hoodie, black gloves, grey jogging bottoms, black shoes and wearing chains."