Visitors to the German Web site of Google were met with a strange sight early Tuesday morning: Gone was the Google logo, replaced by the name of a local Internet service provider with the message that no content was available for the domain.

The Internet address of google.de and the page name were transferred to the new ISP, Goneo Internet GmbH, in a domain name grab that has confused Google users and infuriated company officials.

"This has never happened to google.de, and believe me, it will never happen again," said Google Deutschland spokesman Stefan Keuchel. He couldn't explain who is responsible for triggering the transfer and said the incident is under investigation.

The world's most-used Internet search engine was the victim of a domain name grab similar to the coup on the German Web site of the globe's most used online auction service, eBay, in 2004.

Not all of Google's German Web sites were affected by the domain grab, and those that were got restored within approximately two hours, according to Kreuchel.

The spokesman declined to comment on what action the company plans to take to prevent its domain from being kidnapped in the future. "This is internal," he said. "But rest assured; there will be changes."

In Google's case, two key security measures to prevent domain hijacking failed, a situation that could lead to changes in German domain name regulations, according to German domain registry Denic eG.

Neither Google's existing ISP nor the service provider selected to take over the search giant's German domain conducted the necessary checks for a domain to change ownership, according to Keuchel. Google didn't disclose the name of the ISP that released the domain name.

These include, for instance, that the service provider submitting a domain change confirm in advance the identity of the company or individual requesting the change, according to Denic. In this case, Goneo should have run a check on Google Deutschland. The ISP hosting a domain name should also reject a requested change if it's uncertain about its legitimacy.

"Both checks appear not to have functioned," Denic said in a statement. "A contract was submitted to change service provider, although Google had no intention of making a change."