A murder trial jury has heard expert witness evidence given on a live-video link from Australia.

Ronald Wheeler appeared on television screens at Bradford Crown Court today to describe how he could accurately calculate a person's height from CCTV footage.

Michael Metcalfe is accused of murdering father-of-six taxi driver Mahmood Ahmed after he collected a late-night fare outside the Merry Melon flower shop in Oakworth Road, Keighley last April.

The body was dumped on Slack Lane, Oakworth where it was discovered by a man walking his dog the next morning.

Metcalfe, 46, of Parkwood Rise, Keighley, denies murder but the prosecution have alleged that he stabbed Mr Ahmed in the chest and then repeatedly struck him with a hammer.

Mr Wheeler told the jury from a secure room in Brisbane that a person seen on CCTV loitering outside the Merry Melon on the day of the killing was 1.71 meters tall, a measurement that he said was accurate to two centimetres.

Prosecutor Simon Myerson QC told the jury that the Crown alleges that the man in the footage is the defendant.

Under cross-examination from Metcalfe's barrister Neil Davey QC, Mr Wheeler said however, that his measurements included the footwear the person had on and the hat he was wearing.