Thieves stole millions of pounds worth of fuel oil from a pipeline going under the official country estate of the Deputy Prime Minister and Foreign Secretary.
The gang siphoned fuel from the pipe under the state-owned 3,500-acre Chevening estate, near Sevenoaks, which Nick Clegg and Philip Hammond are allowed to use.
It is thought around 30,000 litres of fuel was stolen each day for seven months - at a cost of around £8.3m.
The Sun said the fuel was funnelled along a 1,600ft pipe into huge plastic containers aboard lorries and driven away.
A Kent Police spokesman said: "Kent Police was notified of some tampering to a fuel pipeline in the Sevenoaks area on August 6.
"Initial indications are that this was a well organised crime, employing highly specialist techniques to siphon fuel from pipelines which operate at very high pressure."
Chevening has hosted visiting dignitaries such as Italy's Foreign MinisterThe pipe was operated by Esso, which discovered the theft on Wednesday after introducing new security measures.
The South East Pipeline is 120 miles long and carries fuel from Fawley Refinery in Hampshire to Purfleet Fuel Terminal and Gatwick.
Esso said later: "We recently strengthened our pipeline security and monitoring procedures, and on Wednesday detected criminal damage at Chevening on the South East Pipeline.
"The section of pipeline was temporarily shut down to make repairs, which have now been completed.
"There has been no impact on supplies to customers.
"We strongly condemn the highly dangerous criminal action by those involved and are working closely with the police in their criminal investigations."
A spokeswoman for the National Crime Agency said: "We are aware there has been a report of some tampering to a fuel line in Kent and investigations are ongoing.
"If members of the public have any concerns about suspicious activity, such as excavation taking place at an unusual time or at an odd location, our advice is to contact the police, or contact Crimestoppers on 0800 555 111."