Google committed a "significant breach" of British law when its Street View cars grabbed personal data and the firm's branch in the country now faces a probe, a watchdog said today.

Several countries have now taken action against the Internet giant after the cars, which drive around taking photos for Google's free online mapping service, mistakenly picked up private information like emails and passwords from the ether.

British Information Commissioner Christopher Graham said Google's UK arm will face enforcement action if it fails to sign a vow not to commit similar privacy breaches in future and will now be subjected to an audit.

"It is my view that the collection of this information was not fair or lawful and constitutes a significant breach of the first principle of the Data Protection Act," Graham said in a statement.

It said an investigation found Google's Street View cars had collected "fragments of personal data" which it had now been ordered to delete.

"Google UK will be subject to an audit and must sign an undertaking to ensure data protection breaches do not occur again or they will face enforcement action."

The statement said Graham had rejected calls to fine Google over the breaches "but is well placed to take further regulatory action if the undertaking is not fully complied with."

Google UK did not immediately comment on the ruling.

The Californian company has faced strong resistance in some countries to Street View, which enables Internet users to obtain a virtual image of a whole street from every angle due to concerns over invasion of privacy.

Italian prosecutors said last week they had launched an investigation against Google. Spain filed suit against the firm earlier in October while in September Czech authorities banned Google from collecting Street View data.

The US Federal Trade Commission said last week that it was ending its inquiry into Street View, although Google is facing civil suits in several US states demanding millions of dollars in damages.