Bolivian custom officers will have to carry special pens, with a hidden micro-camera and voice recorder, as part of a government initiative to tackle corruption.
The measure was announced by customs director Marlene Ardaya, who will be issued with her own pen.
"They will work as an anti-doping mechanism in the department."
She explained that the voice recorders will remain active during all working hours.
The authorities said officials would be selected randomly to have the recordings in their devices checked.
The Bolivian Customs Department, with more than 1,000 employees, is seen as one of the most corrupt areas of the government in the South American country.
It is supposed to control all import and export, including the sale of valuable mineral resources.
But the Bolivian Economy Ministry estimates smuggling costs the country between $300m (£191m) and $400m a year in lost tax revenue.