Investigators discovered 540kg (1,191lb) of marijuana missing from a police warehouse in Pilar, north-west of Buenos Aires.
The city’s former police commissioner, Javier Specia, and fellow officers told a judge the drugs were “eaten by mice”.
Forensic experts doubted mice would see the drugs as food, and would have probably died if they had eaten it.
A spokesperson for Judge Adrián González Charvay said that according to experts at Buenos Aires University, “mice wouldn’t mistake the drug for food” – and even if they did, “a lot of corpses would have been found in the warehouse”.
The police officers will now testify in front of the judge on 4 May.
The court will decide if the drugs are missing due to “expedience or negligence”.