The Swiss government has decided "in principle to freeze any possible funds Mr Yanukovych may have in Switzerland", foreign ministry spokesman Pierre-Alain Eltschinger told AFP in an email.
The full decision, which would be published on Friday, obliged Swiss banks to show increased vigilance when it comes to Ukrainian funds, he added.
Asked whether Yanukovych or his entourage would be blocked from receiving visas to the country if they were to make such an application, the foreign ministry spokesman would only say that "Switzerland is following very closely the situation in Ukraine."
It is unclear whether Yanukovych himself has funds in the wealthy Alpine nation, but his son Alexander opened a branch of his Management Assets Company (MAKO) in Geneva in late 2011.
The 40-year-old dentist and businessman has amassed a personal fortune of around half a billion dollars (some 365 million euros) in the past three years alone, according to a report in the Swiss weekly L'Hebdo.
His Ukrainian conglomerate reportedly controls nearly half of that country's coal production, and around a third of its electricity production and distribution.