Four of Scotland's most high profile gangland figures have been arrested in Dubai.
BBC Scotland News understands that Steven Lyons, Ross McGill, Stephen Jamieson, and Steven Larwood were taken into custody on Tuesday.
Police Scotland believe all four are linked to criminality ranging from drug importation to a feud between rival criminal gangs in Glasgow and Edinburgh.
The dispute has resulted in a series of assaults, shootings, and firebombings since March.
It is understood detectives have been sharing intelligence with police in the United Arab Emirates, where the men are all based.
It is unclear if officers in Scotland were made aware of the Dubai raids in advance.
And it remains to be seen whether the authorities will press charges or whether moves will be made to extradite the men - who may be deemed a flight risk - back to Scotland.
Detectives working on Operation Portaledge, which was set up in response to the gang violence, have so far made 57 arrests.
Sources have told BBC Scotland News the significance of the Dubai arrests cannot be underestimated.
One said: All four are operating at the highest level of organised crime, both at a UK and an international level.
Steven Lyons is the head of the Lyons crime group, which has been involved in a bloody feud with the rival Daniel clan for more than 20 years.
In 2006, he survived a shooting at a garage in Lambhill, Glasgow, which claimed the life of his cousin, Michael Lyons.
He later moved to Spain before settling in Dubai.
In May, Steven Lyons' brother, Eddie Lyons Jnr, and Ross Monaghan were shot dead in a beachfront bar in Fuengirola on the Costa del Sol. Both men had spent the evening watching the Champions League final before being targeted by a lone gunman.
Michael Riley, 44, from Liverpool, has been accused by Spanish police of the murders with a full extradition hearing scheduled for later this year.
McGill first became known to police for his activities while a senior member of Rangers ultras group, the Union Bears.
But since March, he has emerged as a key figure in the gangland feud which has caused a wave of violence across Scotland.
Larwood is a known associate of Lyons and previously lived in Spain before relocating to Dubai.
Jamieson has links to Jamie Iceman Stevenson, who was jailed for orchestrating a plot to smuggle cocaine worth £100m from South America.
Police Scotland has not confirmed the arrests, and it is understood that the Foreign, Commonwealth & Development Office has not been approached for consular assistance.
Dubai Police referred BBC Scotland News to the UK Embassy in Dubai, which has yet to comment.
