Nathan Fensome, 28, his brother Ashley Fensome, 21, and their cousin Barry Plant, 36, are accused of murdering Steven Fretwell in an attack alleged to have taken place at his Rotherham home in the early hours of December 18 last year.
Police found Mr Fretwell, 47, dead on the floor of his bedroom, bent over in a kneeling position, at his home in Kingswood Avenue, Laughton en le Morthen at 4pm that day.
Opening the case at Sheffield Crown Court this morning, prosecutor, Graham Reeds QC said officers were sent to the scene after one neighbour raised concerns that Mr Fretwell had not been seen that day and another neighbour phoned the emergency services and said they had 'apparently heard sounds of a violent disturbance in his flat in the early hours of the morning'.
Mr Reeds said Barry of Sandymount Road, Wath-upon-Dearne told police he had visited the flat of Mr Fretwell, known locally as 'Chud', between 11pm and midnight on December 17.
Barry said Mr Fretwell had rung Plant's brother, Michael, and told him that he wanted to do some 'business' which he assumed involved drugs and that is the reason they visited.
He said he later returned to Ashley and Nathan's flat, where he was staying at the time.
Mr Reeds said: "It is the prosecution case that all three defendants then agreed to go to Steven Fretwell's flat in the early hours of 18th of December, climbed through his window and attacked him, causing injuries which in turn caused his death."
A post-mortem examination confirmed Mr Fretwell, known locally as 'Chud,' had been 'severely beaten', Mr Reeds told the court.
"The evidence was of a sustained physical assault involving multiple heavy blows from punches, kicks, possibly stamps and the use of one or more types of blunt instrument," said Mr Reeds, adding: "His right wrist was tied with string, as if he had been bound with that string at some point."
In the moments before the the three attackers allegedly arrived at Mr Fretwell's home, his cousin Liam Fretwell arrived at the flat with the car Mr Fretwell had agreed to buy and spoke to him through the window.
The court was told that Mr Fretwell agreed to give Liam Fretwell a lift home, and went to change into his outdoor clothing.
Mr Reeds said: "At this point Liam saw three men, all wearing balaclavas or face masks and staring at him. He said 'who are you' but no-one replied.
"He then ran off and hid in a garden as we was frightened about what would happen to him. As he looked back he could see two of the three men climbing into his uncle's flat through the open window, he ran off before he could see whether all three entered the flat."
He added: "At 01:52.53 three men were recorded running away from the direction away from the direction of 81 Kingswood Avenue, and at 01:56.08 Liam Fretwell was seen walking back towards the address. He said that he looked in through the window of his uncle's flat and could hear him moaning as if he had been beaten up. He could also see blood on his face but he assumed that his uncle would be alright and he did not do anything to assist him. In fact he was picked up by a friend and given a lift home."
The court was told how a few hours before his murder, Mr Fretwell had withdrawn a sum of £200 from his mother's bank account, with her permission, to pay off the balance on a car he was buying.
Mr Reeds said: "The prosecution in a murder case are not required to prove a motive for the killing. However, in this case, the missing wallet full of money points towards the one possible motive having been robbery."
The court was told how Mr Fretwell had been a drug addict for most of his adult life, who had injected heroin for many years and who was a regular user of crack cocaine at the time of his death.
Nathan Fensome and Ashley Fensome, both of Croft Mews, Barleycroft Lane, Dinnington, and Barry Plant all deny one count of murder.
The trial continues.