Google’s UK head of privacy policy was employed by the Information Commissioner’s Office (ICO) during the data watchdog’s investigation into the search giant, it has been revealed.

According to the Guardian, a freedom of information request revealed Stephen McCartney joined Google from the ICO in November 2011.

The ICO was heavily criticised after it took no action against Google over its admission that its Street View camera cars collected personal information from open Wi-Fi networks across the UK. The information it gathered included passwords and even full emails.

Google initially said the data had been gathered in error and that it was "profoundly sorry" that the error occurred.

The ICO investigated the issue and found that although Google had committed a "significant" breach of the Data Protection Act (DPA) that was also "not lawful", no monetary penalty would be issued. The decision was met with a wave of criticism from privacy groups.

In May this year, after McCartney left the ICO, that investigation was reopened. The ICO decided to act again after the publication of a report by the US Federal Communications Commission (FCC) that rejected Google’s claim that it was unaware the data was being harvested.

Instead of being the actions of a single "rogue" engineer, at least two colleagues, including a senior manager, knew the software was capable of gathering data. Google was fined $25,000 at the time, although the penalty was for "wilfully and repeatedly" hampering the investigation, rather than for the collecting of data.

Rob Halfon, Conservative MP for Harlow and one of the most vocal critics of the handling of the issue, told the Guardian: "This is a pretty shocking revelation. It raises more questions about the information commissioner than it does Google because clearly the ICO has been asleep on their watch on this issue."

The ICO has claimed that McCartney was not involved in the original investigation. A statement released to the Guardian said: "Stephen McCartney played no part in the investigation into the Google Street View project while working at ICO. In any event, ICO employees continue to be legally bound by a confidentiality agreement after they leave the organisation, as part of the Data Protection Act."

Google said it does not comment on individual employees.