DETECTIVES are waiting to speak to a badly injured man who could hold the key to a murder inquiry.

Police are treating the death of 41-year-old market trader Kalvant Singh as suspicious.

His body was discovered in the backyard of a house in central Middlesbrough.

Jobless builder Michael Moody, 54, the tenant of the house in Errol Street, is in Middlesbrough General Hospital with bad facial injuries.

Detective Superintendent Mark Braithwaite, joint head of a special murder squad and senior investigating officer, said: "We have not been able to speak to him because of the severity of the injuries.''

The semi-conscious Mr Moody was discovered by his daughter in a downstairs room.

Detectives, responding to her 999 call, found Mr Singh's body lying 15ft below a shattered first-floor window in the same house.

Det Supt Braithwaite said the severe head injuries sustained by Mr Singh, who lives in nearby Croydon Street, were consistent with a fall.

He said: "I am treating his death as a suspicious death.

"There are a number of potential scenarios which could have led to his death and to Mr Moody receiving the injuries he sustained."

A friend gave married Mr Singh a lift home, dropping him off outside his door at about 12.30am on the day of his death.

Det Supt Braithwaite is appealing to anyone who knew Mr Singh or has information about why he went to the house in Errol Street, to contact police.

Neighbours said yesterday that youths visited the house at all hours of the day and night.

They climbed over the back wall of the house and dropped down into the yard, while others sat on the front doorstep, waiting to be admitted.

One resident said she had been offered goods for sale by a woman, who was seen to come and go from the house.

Det Supt Braithwaite said: "I am aware there were a number of visitors to 45 Errol Street.

"Part of my investigation is to identify who these visitors were."

Mr Moody, a married man who lived alone, had only been living in the back street terrace house for about two months.

Det Supt Braithwaite said: "There will be forensic inquiries going on at the address following the discovery of the death. Those inquiries will continue for the rest of this week.''

Cleveland Police have set up an incident room, with the telephone numbers (01642) 303188 and 303189.

Det Supt Braithwaite has a confidential mobile telephone hotline, 07799 773851.