Heathrow Airport fire not a criminal matter, UK police say

British police said a fire which caused Heathrow Airport to close for 18 hours last week was no longer being treated as a potentially criminal matter.

Heathrow, Europe's busiest airport, shut on Friday after a fire at a nearby substation cut its power supply, stranding over 200,000 people, costing airlines millions of pounds and prompting questions over the resilience of UK infrastructure.

On Friday, London's Metropolitan Police said the counter-terrorism unit would lead the investigation into the causes of the fire given the critical nature of the incident.

Reporting back on Tuesday, the police said it was no longer treating the fire as a potentially criminal matter.

"Following enquiries to date, officers have found no evidence to suggest that the incident was suspicious in nature," the police statement said.

The government and Heathrow have both commissioned reviews into what happened, amid the fall-out from the fire which has seen both the airport and National Grid, owner of the sub-station, defending their operations and response.