British top spy agencies briefed Angela Merkel on ISIS threat

London: In a rare exchange of intelligence behind closed doors, Britain's top spy agencies have briefed German Chancellor Angela Merkel on the threat posed by the Islamic State terror group, a UK media report said on THursday.

The German leader, in return, shared information with the heads of MI5, MI6 and Government Communications Headquarters (GCHQ) on Russian President Vladimir Putin, the unrest in Ukraine and the situation in Crimea, The Times newspaper said.

The secret briefing took place with British Prime Minister David Cameron when he hosted Merkel at Chequers, the country house retreat of British Prime Minister, during her visit to the UK in October.

Germany is not a member of the "five eyes" intelligence sharing community which comprises the UK, the US, Australia, New Zealand and Canada.

The meeting, attended by MI5 chief Andrew Parker, Alex Younger of MI6, and Robert Hannigan of the GCHQ listening post, offers a sense of intelligence-sharing behind closed doors between allies at a time of heightened concern over security, the newspaper claims.

"They had a lengthy discussion on Syria and Russia," a Downing Street source told the paper.

The talks took place before the Paris attacks in which 130 people were killed. The atrocities led to calls for greater intelligence sharing in Europe as ISIS militants exploit borderless travel within the EU, coupled with the migrant crisis to avoid capture and plot new attacks.

The intelligence exchange between Britain and Germany went two ways with Merkel who has the closest relationship with Putin. She offered useful information on the Russian President and the situation in Ukraine.

British and German spies exchange information relatively regularly at an official level. It is unusual, however, for the heads of the British intelligence and security services to brief the German Chancellor directly and receive information from her.