The Information Commissioner's Office (ICO) has said that changes to Google's privacy and data protection policies "do not eliminate" the risk of another Street View Wi-Fi data collection fiasco.

The ICO carried out an audit of Google in July after an undertaking signed by the search company in November, and said that, while the watchdog is broadly satisfied with the changes, it is still concerned that a similar event could occur.

"The audit has provided reasonable assurance over the accuracy and findings of the Privacy Report as provided by Google to the ICO. It has also provided reasonable assurance that Google has implemented the privacy process changes outlined in the Undertaking," the ICO said.

"The audit provided reasonable assurance that these changes reduce, but do not eliminate, the risk of an incident similar to the mistaken collection of payload data by Google Street View vehicles occurring again."

Information commissioner Christopher Graham said that he is pleased with the improvement at Google, but warned that the ICO will continue to keep a close eye on the firm.

"The ICO's Google audit is not a rubber stamp for the company's data protection policies," he explained.

"The company needs to ensure that its work in this area continues to evolve alongside new products and technologies. Google will not be filed and forgotten by the ICO."

The regulator did praise a number of new policies implemented by Google, such as Privacy Design Documents, which ensure that all new projects undergo an in-depth assessment so that privacy is built in from the start, and advanced data protection training for engineers.

Alma Whitten, Google's director of privacy, product and engineering, said in a blog post that the company is pleased with the ICO's report, but will continue to work at its policies to ensure they are fit for purpose.

"We welcome their feedback on our progress, and we look forward to working with them to ensure that we continue to develop products that reflect strong privacy standards and practices," she said.

"We know that there is no perfect solution, so we will continue to improve our current processes and develop new ones so that privacy awareness grows and evolves alongside Google."

The audit involved analysing the privacy policies in place and interviewing key members of staff to discuss their understanding of those policies.