Washington (CNN) British and other European intelligence agencies intercepted communications between associates of Donald Trump and Russian officials and other Russian individuals during the campaign and passed on those communications to their US counterparts, US congressional and law enforcement and US and European intelligence sources tell CNN.

The communications were captured during routine surveillance of Russian officials and other Russians known to western intelligence. British and European intelligence agencies, including GCHQ, the British intelligence agency responsible for communications surveillance, were not proactively targeting members of the Trump team but rather picked up these communications during what's known as "incidental collection," these sources tell CNN.

The European intelligence agencies detected multiple communications over several months between the Trump associates and Russian individuals -- and passed on that intelligence to the US. The US and Britain are part of the so-called "Five Eyes" agreement (along with Canada, Australia and New Zealand), which calls for open sharing among member nations of a broad range of intelligence.

The communications are likely to be scrutinized as part of the Senate Intelligence Committee's investigation into Russia's efforts to meddle in the 2016 presidential election.

"If foreign intelligence agencies share information with US intelligence, and it's relevant to the investigation, then of course the intelligence committee will look at it," a source close to the Senate investigation told CNN.

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