The Hellenic Data Protection Authority wants more information.
Greece's data protection agency has banned Google from expanding its Street View service in the country, pending "additional information" from the firm.
Street View gives users a 360-degree view of a road via Google Maps.
Authorities want to know how long the images would be kept on Google's database and what measures it will take to make people aware of privacy rights.
A similar street mapping service, run by local ISP Kapou, was also suspended for the same reason.
In a statement, Google said that it had not seen the full details of the The Hellenic Data Protection Authority's request, but had taken steps to protect people's privacy.
"Google takes privacy very seriously, and that's why we have put in place a number of features, including the blurring of faces and licence plates, to ensure that Street View will respect local norms when it launches in Greece," the statement read.
"We have already spoken with the Hellenic Data Protection Authority to ensure that they understand the importance we place on protecting user privacy.
"Street View has not been banned in Greece. We have received a request for further information and we are happy to continue discussing these issues with them. We will discuss with them whether it is appropriate for us to continue driving in the meantime.
"Although that dialogue is ongoing, we believe that launching in Greece will offer enormous benefits to both Greek users and the people elsewhere who are interested in taking a virtual tour of some of its many tourist attractions."
First launched in the US two years ago, Street View has now covers nine countries, including the United Kingdom and Google wants to expand the service to cover all of Europe.
Users zoom in to a given location in Google Maps, and then drag the "Pegman" icon above the zoom bar on to a given street.
A picture view of that street appears, which users can control to get a 360-degree view of the area or to progress on street level, throughout the city.
Google says the service shows only imagery already visible from public thoroughfares.
However, it has come in for criticism from some quarters, being accused of an invasion of privacy.
While many of these charges have been dismissed, either through the courts or by regional information commissioners, in some cases people have taken a more direct approach.
In April, residents near Milton Keynes blocked the driver of a Google Street View car when he started taking photographs of their homes saying the service was "facilitating crime".
Google's street mapping cars are, for now, being kept in neutral.
The Pentagon has also banned Google from filming near or inside its military bases, saying it posed a "potential threat" to security.
The director of the UK-based privacy watchdog Privacy International, Simon Davies, said the Greeks' decision would set a precedent for other nations.
"This is fantastic news. The Greek regulators understand the risks of future technology creep. They have watched what has happened in the US and UK very carefully and will be familiar with the arguments on both sides.
"This highlights the difference between regulators - some will allow the public space to be exploited, others acknowledge that people's privacy needs to be protected.
"Now we wait for the domino effect, as the Greek decision sets an example that others may follow - we will see what happens next in Central Europe."