The UK-based cellphone company, which directly operates in 29 countries, published the report on Friday outlining details on how governments monitor the communications of their citizens.
According to the report, authorities in some countries require direct access to an operator’s network.
"In those countries, Vodafone will not receive any form of demand for lawful interception access as the relevant agencies and authorities already have permanent access to customer communications via their own direct link," the report read.
Vodafone did not name the countries conducting such operations; however, it did call on governments to amend legislation in a fashion that eavesdropping could only take place on legal grounds.
In response to the report, Shami Chakrabarti, the director of the human rights group Liberty, described the findings as a worst-case scenario infringement into civil rights.
"For governments to access phone calls at the flick of a switch is unprecedented and terrifying," said Chakrabarti.The cellphone company began working on the report last year following the leaks by US whistleblower Edward Snowden on government spying.
In June 2013, Snowden leaked top secret US government spying programs under which the NSA and the Federal Bureau of Investigation (FBI) are eavesdropping on millions of American and European phone records and the Internet data from major Internet companies such as Facebook, Yahoo, Google, Apple, and Microsoft.
The NSA scandal took even broader dimensions when Snowden revealed information about its espionage activities targeting friendly countries including other European countries such as France.