The world's largest wealth manager says all its staff can travel freely to and from China, responding to media reports that the bank had warned employees about a potential problem.

UBS has assured staff and clients that employees can travel to and from China without hindrance, following reports that it had warned managers about visiting the country amid an investigation.

At the weekend, media reports said that the Zurich-listed bank had warned some staff against travelling to the country after China had asked one of the firm’s managers to help an investigation. Reports from the Wall Street Journal had cited unnamed sources. The nature of that probe, concerning a woman based in Singapore but now in Beijing, was not known, reports said.

“UBS would like to confirm that we allow all our staff to travel freely in and out of the country and it is business as usual for us in China,” a statement emailed by the bank to this news service said.

“UBS has had a strong franchise in China for 30 years and remains fully committed to further developing our business on the mainland,” it said.

Such a restriction on travel to China would have been a blow to a bank that has aggressively stepped up Asia its operations in recent years, as have Swiss rivals Credit Suisse and Julius Baer.