The classified letter is dated July 15, 2014.
Spokesperson Charity Chanda said in an interview in Lusaka yesterday that police are studying the matter and will inform the nation once they are through with investigations.
“We will inform the nation once we are through with investigations over the issue of the leaked letter,” Ms Chanda said.
She could, however, not tell how long the probe will take.
On Tuesday, Mr Chikwanda said at a media briefing in Lusaka that law enforcement agencies should protect Government’s confidentiality and integrity by establishing how a classified document got into the possession of unauthorised persons.
“It is Government’s duty to ensure legality and propriety. It is incumbent upon Government to foster a conducive environment for investors, local and foreign, by streamlining the enforcement of practices or regulations which have the potential of creating a disenabling atmosphere,” he said.