Italian police have arrested a member of a family allegedly linked to Mafia deaths in Germany last year.
Paolo Nirta, 31, the suspected acting head of the Nirta-Strangio clan, was seized in a raid in the small southern town of San Luca, police said.
His father and brother have also been arrested over the killings in Duisburg of six men from a rival clan of the Calabrian mafia, the 'Ndrangheta.
The authorities believe the killings were part of a long-running vendetta.
The six Italian men, all linked to the Pelle-Votari clan, were shot dead outside a pizza restaurant on 15 August after a birthday party celebration.
Paolo Nirta's brother, Giovanni Luca, was arrested within weeks in connection with the killings. Their father, Giuseppe Nirta, was taken into custody in southern Italy in May this year.
About 100 police officers supported by helicopters swooped at dawn on Thursday on the town of San Luca, says the BBC's David Willey in Rome.
They broke down the door of an old house and seized Paolo Nirta without a fight just as he was trying to escape from a balcony.
Giuseppe Nirta was arrested in the Calabrian region in May
He will appear shortly before a local court in connection with a series of vendetta killings carried out in recent years by two of the families allegedly battling for control of the cocaine trade in Europe, our correspondent says.
The Calabria-based 'Ndrangheta has become one of the most powerful criminal organisations in Italy, our correspondent adds, having overtaken the Sicilian mafia, the Cosa Nostra, in the expansion of its international drug trafficking activities inside Europe
Researchers say the 'Ndrangheta makes nearly $70bn (45bn euros) a year, the equivalent of 3% of Italy's gross national product, from its criminal activities, which include extortion rackets, people smuggling and money laundering.
Unlike the Sicilian Mafia, the Calabrian crime syndicates remain under traditionally tight family control and police find it difficult to infiltrate their criminal activities using normal investigative techniques, our correspondent says.
For more than a decade, San Luca, a town of about 4,500 at the southern tip of Italy, has been the focal point of a bitter feud between rival clans among the 'Ndrangheta - notorious for vendettas.
The feud dates back to an egg-throwing incident in 1991, when a fight broke out which left two young men dead and another two injured.
The murder of Paolo Nirta's sister-in-law on Christmas Day 2006 is also believed to be linked to the feud.