Safrajur Jahangir, aged 23, from Darnall, was killed in August 2009 after he was lured to Scraith Wood Drive, Shirecliffe, after a bogus telephone order for a curry was placed.
He was shot at point blank range by a gunman who was lying in wait for him to pull up outside a house.
Safrajur, who was known as Shaju to his family and friends and ran the Spice Hut on Middlewood Road, Hillsborough, was said by detectives at the time to have been killed in an ‘organised hit’.
Six men went on trial in 2010 accused of conspiracy to murder, with detectives believing they were all involved in a plot to kill.
It was claimed by the prosecution that a hitman had been paid £15,000 to carry out the shooting but that he later died of a heroin overdose.
The police probe had focused on a long-running feud between two Asian families.
But the trial of the suspects collapsed in what was called a 'disaster for the criminal justice system' and the men walked free.
A seventh man, who was also charged over the murder but had been deemed unfit to stand trial, was also found not guilty.
The murder trial was halted when it emerged that South Yorkshire Police had failed to disclose to the defence teams all the evidence gathered by the force during the investigation, denying the defendants a fair trial.
Nobody else has ever been arrested or charged over the murder since the case collapsed.
It is one of 32 murder cases which have never been solved in South Yorkshire since the 1960s, including three other fatal shootings.
In 1996, Andrew George Bentley was shot dead at the Flying Pizza restaurant on Glossop Road in Sheffield city centre.
Jonathon Matondo, 16, was shot on the Nottingham Cliff recreation ground in Burngreave in 2007 and James Kamara, 22, was gunned down in Brunswick Street, Broomhall, in 2009.
There are 12 other live murder investigations currently under way in South Yorkshire following deaths over the last year.