Russian plumbers do not tend to summer in Davos. Even those with diplomatic passports.

Five months before world leaders began their pilgrimage to the annual World Economic Forum this week — among them US president Donald Trump — Swiss police interrupted what reports on Tuesday claimed were the beginnings of a Russian spying operation in the secluded Alpine town.

Alerted to their unusually long stay in the high-end resort, police picked up two Russian men in Davos in August, the Graubünden cantonal police department confirmed to the Financial Times.

The men claimed diplomatic protections, but had not been registered as official diplomats with Bern, the police said.

No indications of criminal acts were found at the time, the police added.

According to Zürich’s Tages-Anzeiger newspaper, which carried a detailed report of the incident, police and Swiss federal officials suspected the pair of being Russian intelligence agents, posing as tradesmen in order to install surveillance equipment at key facilities around the town to monitor the private conversations of the world’s powerful and wealthy during the World Economic Forum on behalf of the Kremlin.

The Russian embassy in Bern did not respond to a request for comment.

Though many may doubt how much actionable intelligence even the most subtle of agents could lift from the World Economic Forum, the gathering is nevertheless a rare concentration of global power and influence that is tempting to spymasters. Alongside Mr Trump — and his retinue, among them his daughter Ivanka and her husband Jared Kushner — other leaders of potential interest to the Kremlin attending this year include president of the European Commission Ursula von der Leyen, Ukraine’s president Volodymyr Zelensky and Hong Kong’s chief executive Carrie Lam, not to mention hundreds of chief executives and senior government officials.

Read more: ft