I simply can not find source in the original Swiss article. The most relevant part of the article is:

The Federal Intelligence Service (NDB) confirms on request that the Swiss authorities are aware of "the case of the Russian spies who were discovered in the Hague and then taken away". NDB communications chief Isabelle Graber also writes: "The NDB has actively participated in this operation, together with its Dutch and British partners." This has contributed to the "prevention of illegal actions against a critical Swiss infrastructure".

How's that related to the two guys detained in Netherlands? I mean, the accusation of them being targeted Swiss lab?

How can I be sure this is not a sensationalist fantasy of a journo?

It would be good to publish the full report from NDB.