Zimbabwe's President Robert Mugabe has approved a new law allowing the security services to intercept postal, internet and telephone communications.
Zimbabwe has the world's highest inflation rate - 4,500%
The law also establishes a state-run communications monitoring centre.
Officials say the new law is meant to provide security and prevent crime but critics say it is aimed at stifling opposition to Mr Mugabe.
Zimbabwe is undergoing an economic crisis with hyper-inflation, fuel and food shortages and high unemployment.
Both houses of parliament approved the new law in June.
The United Nations World Food Programme warned on Wednesday that hundreds of thousands of Zimbabweans are running out of food due to a poor harvest and the worsening economic situation.
Inflation is running at 4,500% - the world's highest - and 80% of the work force is unemployed.
Three million Zimbabweans have left the country and another 3.3 million rely on food aid.