The entire police force in the coastal Mexican resort of Acapulco is under investigation amid suspicions of infiltration by drug gangs.
Two commanders accused of murder are being sought while the rest of the city's police have been disarmed.
State police and the military will patrol the city instead.
Acapulco became famous as a destination for the rich and famous but it has fallen prey to the drugs trade and has a rampant murder rate.
Last year, it stood at 103 per 100,000 inhabitants, one of the highest in Mexico.
The state where the city is located, Guerrero, is one of the most violent in the country with criminal gangs controlling areas where poppies are grown to create heroin.
Federal investigators said they had taken the step "because of suspicion that the force had probably been infiltrated by criminal groups" and the "complete inaction" in fighting crime.
With low pay and little training, local police in Mexico can be an easy target for drug cartels.
There have been reports that the gangs offer them money to obey their leaders, and threaten to kill them if they do not.
Local police in other parts of Mexico have been disbanded amid concerns they were in the pay of drug cartels.