The founder of the Telegram messaging app, Pavel Durov, said on Sunday he had refused a request by a Western government, which he did not name, to "silence" conservative voices in Romania ahead of a presidential election run-off there.

Romanians were voting on Sunday in a run-off that pits a hard-right eurosceptic against a centrist independent. The outcome of the contest will have significant implications for both Romania's struggling economy and European Union unity.

The vote takes place nearly six months after the initial ballot was canceled because of alleged Russian interference - denied by Moscow - in favor of far-right frontrunner Calin Georgescu, who was banned from standing again.

"A Western European government... approached Telegram, asking us to silence conservative voices in Romania ahead of today's presidential elections. I flatly refused," Durov wrote on Telegram.

"Telegram will not restrict the freedoms of Romanian users or block their political channels," Durov said, adding to his post an emoji of a baguette which might hint at France.

"You can't 'defend democracy' by destroying democracy. You can't 'fight election interference' by interfering with elections. You either have freedom of speech and fair elections — or you don't. And the Romanian people deserve both," he said.

Durov, born in Russia but now a French national, was detained last year in France amid an investigation into crimes related to child pornography, drug trafficking and fraudulent transactions associated with the app.

In March Durov, who denied any wrongdoing, returned to Dubai. Telegram is widely used in Russia, including by the authorities and officials, and in Eastern Europe.