Wireless telecom company Vodafone has disclosed that it opens its network to government agencies in six countries so they can listen to and record customers’ calls.

Vodafone, the world’s second-biggest cellphone company after China Mobile, said it could not name the countries involved for legal reasons. A British-based phone company with extensive operations in Europe, the Middle East and Asia, Vodafone does not operate in Canada.

The company released a report Friday detailing demands for information from government from 29 of the countries where it operates, unveiling a picture of widespread government surveillance.

While most governments needed legal notices or warrants to tap into customers' communications, there were six countries where that was not the case, it said.

"In a small number of countries the law dictates that specific agencies and authorities must have direct access to an operator's network, bypassing any form of operational control over lawful interception on the part of the operator," Vodafone said.

In those countries government agencies tap directly into Vodafone networks and can listen in or upload data without the company knowing, it said.

Neither Canada nor the U.S. is mentioned in its report – Vodafone ended its association with U.S. wireless provider Verizon earlier this year and only just struck a new deal with Rogers Communications in Canada.

This week both Rogers and TekSavvy have released details of how often they get requests for information about customers in Canada, in the wake of a privacy commissioner report that revealed the government made 1.2 million requests to telecom firms in the past year.

The company said has broken its silence on government surveillance in order to push back against the increasingly widespread use of phone and broadband networks to spy on citizens.

  "The need for governments to balance their duty to protect the state and its citizens against their duty to protect individual privacy is now the focus of a significant global public debate," the company said in the report. "We hope that ... disclosures in this report will help inform that debate."

The report shows 515,000 requests for metadata in the U.K., 685,000 in Australia and 605,000 in Italy.

But of greater concern to privacy experts is the news that several countries prohibit Vodafone from revealing the extent to which it hands over data, among them Albania, Egypt, Hungary, India, Malta, Qatar, Romania, South Africa and Turkey.

The extent of U.S., Canadian and British surveillance was laid bare by NSA whistleblower Edward Snowden who passed secret documents to newspapers detailing government spy practices.

With files from Associated Press, Reuters