Prosecutors working the criminal case surrounding the deaths of Johnny and Matthew Gaudreau are asking a judge to rule the brothers' BAC levels inadmissible as evidence.

Officials at the Salem County Prosecutor's Office in New Jersey filed court documents on Wednesday ... arguing the Gaudreau bros' intoxication measurements should not be presented to the jury -- stating they're "irrelevant" to the charges levied against the Gaudreau's alleged killer, Sean Higgins.

The authorities stated in the docs, obtained by TMZ Sports, "Multiple witness accounts show that it was the defendant's actions and his actions alone that caused the collision that led to Matthew and John Gaudreau’s deaths."

They added, "the contents of the toxicology reports and the way the brothers were operating their bicycles on the day in question are irrelevant."

As we previously reported, Higgins' attorneys say the toxicology reports showed Johnny's BAC was .129 and Matthew's was .134 ... both higher than Higgins' .087. But Higgins' attorneys have not yet specifically argued how those results factor into the case.

Parties on both sides are expected to appear before a judge on April 15 -- but it's unclear if a ruling on the prosecutors' motion will be made then.

As we reported, Higgins allegedly ran over the Gaudreaus on Aug. 29, 2024 ... as the two were biking on an N.J. roadway. Johnny, an NHL superstar, was 31, Matthew was 29.