A 20-year-old has been arrested on suspicion of the murder of an elderly man who is believed to have been attacked during a burglary at his home.
Joseph Griffiths, 73, was found dead at his home in Fulham, west London, on Saturday after police were called to investigate a break-in.
A 20-year-old man was arrested on Tuesday morning on suspicion of murder and is in custody at a central London police station, said Scotland Yard.
The arrest comes after relatives of Mr Griffiths, who was married with two grown-up sons, paid tribute to his sense of humour and said his death would leave a "great void" in their lives.
In a statement, his family said: "Joe was a husband, father and grandfather, he was a successful businessman who embraced life and lived it to the full.
"He took great pride in his business and it gave him immense satisfaction that three generations of the Griffiths family were employed there. Joe's sudden and tragic demise has shocked and saddened all who knew and loved him, and has left a great void in all our lives."
Police said officers were called at around 6.20am on Saturday to reports of a burglary at Hazlebury Road. A man inside the address had suffered a violent attack, and was pronounced dead at the scene, they said.
A post-mortem examination confirmed he was stabbed. There were other people in the house at the time but none were injured.
Scotland Yard said officers are keeping an open mind on the motive for the attack, but one line of inquiry is that it appears Mr Griffiths disturbed an intruder.