A fifth man was being questioned today over the murder of a farmer believed to have been killed in a botched robbery, police said.
Julian Gardner, 53, suffered multiple injuries after apparently disturbing intruders at isolated Bush Barn Farm in Robertsbridge, East Sussex.
His body was found by his business partner on October 11, with the murder believed to have taken place some time after 11pm the previous day.
A spokeswoman for Sussex Police said: "A 56-year-old man from Ashford, Kent, presented himself at Eastbourne custody centre today and has been arrested for murder.
"He is currently being interviewed in relation to the death of Julian Gardner."
Two search warrants were conducted by officers at addresses in Kent last week.
A 31-year-old man was arrested in north Wales on Thursday and another man of the same age was arrested at an address in Ashford on Friday. Both were released without charge and granted police bail until January.
Meanwhile two other men aged 29 and 40, both from Ashford, were arrested in October and are due to answer bail later this month.
Detectives believe Mr Gardner may have disturbed somebody trying to break into outbuildings at the farm where he ran an agricultural and car repair business.
One theory is that his compression-type injuries were sustained when he was crushed between two vehicles.
Forensic searches have been carried out on a burned-out Jeep Cherokee, which had been in for repair at Mr Gardner's business and was found hours after the killing in Sandhurst, Kent, a few miles from the farm.
A second 4x4, a Land Rover Defender owned by Mr Gardner, was also discovered burned-out at Cripps Corner, near Battle, and has been forensically examined.
Police said inquiries into Mr Gardner's background found nothing to suggest he might have been the victim of a grudge attack.
His death came just days after a campaign to keep locals safe, with police, crime prevention officers, locksmiths and alarm firms offering tips to prevent burglaries. Police said there was no evidence that he had been burgled in the past.
In October last year he reported to police an attempted theft of vehicle batteries from his farm off the A21.
Youths had tried to flee after putting the batteries in a wheelbarrow but they abandoned them when they were disturbed by a neighbour.
It has emerged that Mr Gardner's 90-year-old widowed mother was asleep in the main farmhouse when her son was killed. In a statement, Molly Gardner said her life and that of his sister, Anna Murphy, would never be the same again, adding: "The space he leaves will never be filled."
Anyone with information is asked to call police on 0845 6070 999, quoting Operation Bradford, or Crimestoppers on 0800 555 111.