Ms Merkel warned Russia about the consequences on Wednesday after she claimed Russian intelligence services hacked her emails. “We always reserve the right to take measures, including against Russia,” Mrs Merkel told the German parliament.

Germany has “hard evidence” Russian hackers conducted a 2015 hacking attack in which her emails were jeopardised, she said.

The Chancellor officially made the claims after the German press had been reporting on the developments for several days.

“I can honestly say that it pains me,” Mrs Merkel said, as she called out Russia’s “outrageous” behaviour.

“Every day I try to build a better relationship with Russia, and on the other hand there is hard evidence that Russian forces are doing this.”

The alleged hacking attack took place in 2015 with the German parliament’s internal computer system as target.

Several MP’s email accounts were out at risk.

Spiegel magazine reported last week that Ms Merkel’s email account was also compromised.

German prosecutors issued an international arrest warrant against a Russian hacker named as Dmitri Badin last week.

German media outlets have reported widely that Mr Badin is thought to have been operating on behalf of Russia’s GRU military intelligence service.

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Germany expelled two Russian diplomats only month ago and accused the Kremlin of not cooperating with inquiries into the murder of a Georgian man in Berlin.

German prosecutors are reportedly certain Russian intelligence was behind the murder of Zelimkhan Khangoshvili, a Georgian who fought against Russia in the Chechnya war.

The killing of Mr Khangoshvili has been dubbed a “second Skripal case.”

He was shot dead in a central Berlin park during the day.

A Russian citizen remains detained over the murder but prosecutors reportedly believe he was working on behalf of the Kremlin.

Ms Merkel faced off Vladimir Putin in all-night discussions to alleviate the Ukraine crisis in 2015, and the two leaders have frequently bumped heads over the years.

Mr Putin famously had a dog brought into the room to make nervous Mrs Merkel during discussions in 2007 — the German leader was badly attacked by one as a child and is anxious of dogs.

After the incident, speaking to reporters Ms Merkel said: “I understand why he has to do this — to prove he’s a man. He’s afraid of his own weakness.

“Russia has nothing, no successful politics or economy. All they have is this.”