OCPD Asst Comm Abang Ahmad Abang Julai said the incident occurred Sunday night when police stopped a Perodua Kancil at a roadblock in Jalan Matang Baru.
While police were checking the boot of the car, a 44-year-old man came out and hurled abusive words at them.
He then tried to grab an HK-MP5 sub-machine gun carried by a lance-corporal at the roadblock.
As he was being detained, his 41-year-old wife came out baring her chest and daring police to arrest her.
She was then arrested with the help of a policewoman.
In the process of being arrested, the couple bit the arms of a constable and a corporal.
Police believe that the male suspect was drunk at the time of the incident.
The couple have been remanded for four days and the case is being investigated under Section 186 of the Penal Code for obstructing a public servant in the discharge of his duties.