Romania's constitutional court has annulled the result of the first round of voting in the presidential election just days before the second round was due to take place.

It means the process will be restarted from scratch, with the government due to decide a date for a new vote.

The first round was won by Calin Georgescu, an almost unknown far-right Nato-sceptic who has previously praised Vladimir Putin.

The court's decision comes after intelligence documents were declassified, suggesting Georgescu benefitted from a mass influence operation – conducted from abroad – to interfere with the result of the vote.