Regulators opened a disciplinary investigation last month looking into a series of meetings that Lauber had with FIFA president Gianni Infantino, who is also Swiss.
The Swiss Federal Criminal Tribunal said that Lauber's conduct was not consistent with the rules governing the country's top prosecutor and highlighted that his FIFA meetings only came to light through media investigations.
Two Lauber-Infantino meetings were exposed last year by “Football Leaks”, a cross-border investigation by several European news organisations.
The body that oversees Lauber's office, known as the AS-MPC, has said that those two 2016 contacts, held shortly after Infantino took charge of FIFA from the disgraced Sepp Blatter, were “not problematic.”
But during the inquiry into those two meetings, Lauber told the oversight body that he had had no other informal contacts with Infantino.
Then Swiss media reported a third Lauber-Infantino meeting in January 2017.
Switzerland's FIFA investigation concerns alleged misconduct that occurred before Infantino replaced Blatter in 2016.
Lauber's office has steadfastly defended the Infantino meetings, insisting they were logistically necessary given the scope of the FIFA graft probe.
But the court specifically raised doubt as to why the attorney general's presence would have been “essential” at simple organisational meetings, which could have been handled by more junior staff.
In a press conference last month, Lauber dismissed suggestions that he had deliberately concealed the truth and announced his desire to serve another term as attorney general, which would run from 2020 to 2023.
Switzerland has pursued a number of cases since a raid on a luxury hotel in Zurich in May 2015 led to the arrests of a several FIFA executives and exposed the corrupt underbelly of world football.
Tuesday's developments in the Swiss probe were unrelated to events in France, where former UEFA boss and football legend Michel Platini was held for questioning in connection with a criminal investigation into the awarding of the 2022 World Cup to Qatar.