Google is facing a fresh investigation by the information watchdog after renewed concerns over data collected from cars talking pictures for the company's controversial Street View service.

The Information Commissioner's Office (ICO) had previously been assured that private data had been "mistakenly collected" by the cars as they gathered photographs for Street View. But an investigation by the Federal Communications Commission (FCC) into the way that Street View was managed in the United States has caused the ICO to reopen its inquiry in Britain. The FCC found that Street View cars in the US had been used to gather a wide range of personal and private data from wi-fi networks. Steve Eckersley, head of enforcement at the ICO, has written to Alan Eustace, senior vice-president at Google, demanding details about what information was collected in the UK and whether it has since been destroyed.

The ICO, which enforces data-protection legislation, said the FCC investigation had found that the Street View data collection in the US had resulted in Google's capture of "complete email messages, email headings, instant messages and their content, logging-in credentials, medical listings and legal infractions, information in relation to online dating and visits to pornographic sites".

The ICO noted that "it therefore seems likely that such information was deliberately captured during [Google Street View] operations conducted in the UK".

Google has said that it is happy to answer the ICO's questions and that it has not acted on the information it collected.