Privacy International (PI) has accused Google of intentionally breaking the law in collecting Wi-Fi data during its Street View work.
The body slammed Google's claim that the acquisition of data over networks in numerous countries across the world was a mistake.
Google said earlier this month that an engineer had written a piece of code in 2006 for an "experimental Wi-Fi project", and this was then unwittingly employed in software used by the organisation's mobile team when it was collecting "basic Wi-Fi network data" a year later.
Subsequently, Google announced on its blog this week that a third-party report on the software involved had been sent to data protection authorities across the world. The search firm admitted that the report essentially shows Google had collected and stored payload data from unencrypted Wi-Fi networks, but not from encrypted ones.
PI has now said that Google's explanation is erroneous and that the new analysis shows the firm intended to take the information.
"This analysis establishes that Google did, beyond reasonable doubt, have intent to systematically intercept and record the content of communications and thus places the company at risk of criminal prosecution in almost all the 30 jurisdictions in which the system was used," a statement from PI said.
"This action goes well beyond the "mistake" promoted by Google. It is a criminal act commissioned with intent to breach the privacy of communications. The communications law of nearly all countries permits the interception and recording of content of communications only if a police or judicial warrant is issued," the non-profit organisation added.
Google has come under fire in a number of countries, including Germany, France, Italy and Spain. In Australia, the country's attorney general has asked police to investigate the company.
"We are continuing to work with the relevant authorities to respond to their questions and concerns," Google said.
With the Information Commissioner's Office saying that it is happy with Google's promise to delete the data as soon as it can, it appears PI may be taking matters into its own hands. Head of the privacy body Simon Davies has told the BBC that he sees no other option than to go to Scotland Yard about the case.
