The document,  leaked by the former NSA contractor Edward Snowden and drafted on April 17 by an officer at the US's National Security Agency, summarises the agency's co-operation with Norwegian intelligence. 

 

It notes Norwegian intelligence's good access to both "Russian targets in the Kola Peninsula" and  Russian "civilian targets…especially Russian energy policy". 

 

It also claims that the NSA has successfully expanded and deepened intelligence exchange around Russian "political, natural resources and energy issues". 

 

Lieutenant General Kjell Grandhagen, the head of Norway's intelligence service, or E-Service, confirmed that the document appeared genuine, but stressed that the activities described were all permitted under Norwegian law. 

 

"The document Dagbladet has accessed is an internal NSA document E-service has not previously seen," he told Dagbladet. "The document bears the mark of being drafted by an American officer and E-service will not necessarily stand behind all of the formulations used."

 

He claimed that his agency did not engage in industrial espionage, despite the apparent focus on Russia's energy industry. 

 

Russia's Kola peninsular, which borders Norway's far-North, was the Soviet Union's main naval and nuclear weapons base, and today still has the highest concentration of nuclear weapons, reactors, and facilities in Russia. 

 

It is also the base from which Russia is seeking to develop potential massive new oil and gas developments in the Russian sector of the Barents Sea. 

 

Norway's Statoil-Hydro in 2008 formed Shtokman Development AG, a consortium with Russia's Gazprom to develop the giant offshore Shtokman field, only for the consortium to collapse in 2012, forcing Statoil to write off its investment of two million kroner ($336m). 

 

Dagbladet has been working together with the US journalist Glenn Greenwald to report on leaked NSA documents concerning Norway. 

 

It reported last month that the NSA had collected 33m pieces of data from Norwegians' phone communications in a single month, a claim Grundhagen dismissed, arguing that the document in fact referred to 33m pieces of phone data collected by Norwegian intelligence from sources outside the country.