Scotland Yard has launched a double murder investigation after a body discovered in a car boot was linked to a man found stabbed to death five miles away.
Detectives investigating the deaths of the two two eastern European men said they cannot rule out "a potential organised criminal element".
Officers arrived at the scene in Courtland Avenue but there was no sign of any victim or suspects.
Less than 20 minutes later, police and paramedics were called to reports of a man with stab injuries at nearby Barnet Bypass, next to Scratchwood Park. The 31-year-old man was treated at the scene before being taken to hospital.
Police searched a car found at the scene and discovered a 30-year-old man with stab wounds inside the boot.
Despite the efforts of emergency services, he was declared dead a short time later.
Police are attempting to track down his next of kin and formal identification is yet to take place.
The 31-year-old man found at the scene was subsequently arrested on suspicion of murder and has been taken into custody upon discharge from hospital.
He currently remains in police custody.
The second man, 35, was discovered with stab wounds in undergrowth in Hogg Lane, Elstree, Hertfordshire, on Friday afternoon. He was pronounced dead at the scene.
Detectives are treating the deaths of the two men, who are both believed to be eastern European, as linked and said a “fast-moving” murder investigation is underway.
Officers are working to establish how long the body had been lying in the undergrowth in Hertfordshire, and whether the victim died before or after the discovery in Barnet.
Post-mortem examinations for both victims are due to be scheduled. Their families are being supported by specialist officers.
Detective Chief Inspector Simon Stancombe, of the Metropolitan Police, said: “At these very early stages, we believe both the deceased men are Eastern European males.
“While we retain an open mind as to a motive, we cannot rule out whether there might be a potential organised criminal element.
“We also believe that the two victims might have been known to each other.
“I am asking those residents who live in the vicinity of the crime scenes in Barnet and Elstree to think very carefully about anything suspicious you may have seen over the last few days, and to make contact with us immediately.
“I would also like to reassure them that events of this nature are very rare, however if they have any concerns to contact their local neighbourhood officers.”
Police said they were particularly keen to hear from anyone who may have information about suspicious vehicles being driven erratically in the Barnet or Elstree areas.
Mr Stancombe added: “It could be that you may have caught something via dashcam footage that could prove massively important.
“The slightest fragment of information could prove crucial, so even if it may seem insignificant, please call the incident room or make use of anonymous methods such as the independent charity Crimestoppers.”