Hundreds of German politicians, including Chancellor Angela Merkel, have fallen victim to a massive hacking attack after which private data was leaked online, the government said Friday.

The leak, which saw data posted in daily batches on Twitter last month, affects all parties in parliament except the far-right Alternative for Germany, public broadcaster RBB reported.

A spokesperson said no 'sensitive' information had been published online from the Chancellor's office, following reports that a fax number and email address belonging to Mrs Merkel was leaked, as well as several letters to and from her.

Hacked: Chancellor Angela Merkel is one of hundreds of German high-ranking politicians targeted by hackers, however no sensitive data or information has been leaked

'With regard to the chancellery it seems that, judging by the initial review, no sensitive information and data have been published and this includes (from) the chancellor,' the spokeswoman told a regular government news conference on Friday.

The stolen data, which comprised personal addresses, mobile phone numbers, letters, invoices and copies of identity documents, was published online via Twitter in December but inexplicably only came to light this week.

Beyond politicians, who also included President Frank-Walter Steinmeier, celebrities and journalists were also targeted.

There was no immediate information on who was responsible or on the source or sources of the data, and whether they were all authentic.

Alexander Dobrindt, the conservative Christian Social Union's top lawmaker in Berlin, said that authorities were working to establish 'what data are affected and to what extent.'

Singled out: The only party whose members did not seen their private information posted on the Twitter account is the German far-right AfD party

German daily newspaper Bild said the theft of the data continued until the end of October but it was not clear when it started.

'At first glance it does not seem that politically sensitive material was included,' RBB said.

'However the damage is likely to be massive given the volume of personal data published.'

Targeted: German President Frank-Walter Steinmeier was also targeted by hackers

Given the vast range of data hoovered up, RBB said it seemed unlikely that it was taken from a single source.

Parliamentary group leaders were notified of the attack late Thursday and the Federal Office for Information Security (BSI) and the domestic intelligence service said they were investigating.

'According to our current information, government networks have not been targeted,' BSI tweeted.

The now-suspended Twitter account @_0rbit published the links daily in the style of an advent calendar, with each entry representing a 'door', behind which was a link to new information.

The account, calling itself G0d, was opened in mid-2017 and purportedly has more then 18,000 followers.

It described its activities as 'security researching', 'artist' and 'satire and irony' and said it was based in Hamburg.

The domestic intelligence service, the Office for the Protection of the Constitution, reported repeated cyberattacks last year against MPs, the military and several embassies allegedly carried out by Russian cyber espionage group 'Snake'.

Also known as 'Turla' or 'Uruburos', the group, which targets state departments and embassies worldwide, is believed to have links to Russian intelligence.

Last March, computer networks belonging to the German government came under sustained attack and data from foreign ministry staff were stolen.

The Russian government at the time denied that Russian hackers were involved.