Tony Martin, the Norfolk farmer jailed for shooting dead a teenage burglar, has been arrested for possession of an illegal firearm, sources said.
Martin, 71, served three years in prison for shooting dead Fred Barras, 16, at his home in Emneth Hungate, Norfolk, in 1999. He was initially found guilty of murder but this was reduced to manslaughter on appeal.
A Norfolk Police spokesman said on Thursday: "As part of a planned operation, a 71-year-old man has been arrested in Wisbech this morning on suspicion of possession of an illegal firearm. He remains in police custody.
"A police search of a property in Emneth Hungate is currently being undertaken."
Mr Martin was living alone at his farmhouse in Emneth Hungate, Norfolk, nicknamed Bleak House, when he caught Brendon Fearon, then 29, and Mr Barras, 16, inside. He fired his shotgun three times towards the intruders, killing Barras.
The case provoked a national debate about the measures homeowners can take to defend their property.
Since being released from prison, Mr Martin is understood to have spent some of his time living on the grounds of the property.
In 2013 he told the Press Association he had once again confronted a burglar at the property.
He said he caught the would-be burglar while checking on an outbuilding. They drove off when he confronted him and he decided not to attempt to stop him, adding: ''I couldn't face going through all that again.''
He said: ''I wished I had but, after everything I've been through in the past, I just couldn't face all that hassle again.
''It isn't the first time it's happened since I've been out of prison - it's happened two or three times.
''I haven't changed my views about what happened in 1999 but the whole experience has made me lose faith in the system and I didn't want to be made out as the criminal again.''
Speaking at the time, Norfolk Police confirmed the incident had been reported to officers but no suspect was ever caught.
Norfolk Police said last night the search would continue throughout Thursday night. Martin remains in police custody.