A huge golden dome has been hoisted atop a new Russian Orthodox cathedral in the heart of Paris, in a ceremony to inaugurate a controversial project championed by Vladimir Putin.

Dignitaries attended Saturday's special blessing of The Saint Trinity church built on the site of the former headquarters of France's national weather forecasting service — near the Seine River and the Eiffel Tower.

The onion dome, which weighs eight tons and is 12 meters high, is the first of five to top the cathedral slated for completion in October.

The site was sold to Russia under former President Nicolas Sarkozy's government amid criticism from rights groups about France's outreach to Putin.

Putin visited the site in 2010 and denied reports that it would be used by Russian secret services.