TOKYO - When Google Earth added historical maps of Japan to its online collection last year, the search giant didn't expect a backlash. The finely detailed woodblock prints have been around for centuries, they were already posted on another website, and a historical map of Tokyo put up in 2006 hadn't caused any problems.

But Google failed to judge how its offering would be received, as it has often done in Japan. The company is now facing inquiries from the Justice Ministry and angry accusations of prejudice because its maps detailed the locations of former low-caste communities.

The maps date back to the country's feudal era, when shoguns ruled and a strict caste system was in place. At the bottom of the hierarchy was a class called the "burakumin," ethnically identical to other Japanese but forced to live in isolation because they did jobs associated with death, such as working with leather, butchering animals, and digging graves.

Castes have long since been abolished, and the old buraku villages have largely faded away or been swallowed by Japan's sprawling metropolises. Today, rights groups say the descendants of burakumin make up about 3 million of the country's 127 million people.

But they still face prejudice, based almost entirely on where they live or their ancestors lived. Moving is little help because employers or parents of potential spouses can hire agencies to check for buraku ancestry through Japan's elaborate family records, which can span 100 years.

An employee at a large, well-known Japanese company who works in personnel and has direct knowledge of its hiring practices, said the company actively screens out burakumin job seekers. "If we suspect that an applicant is a burakumin, we always do a background check to find out," she said. She agreed to discuss the practice only on the condition that neither she nor her company be identified.

Lists of "dirty" addresses circulate on Internet bulletin boards. Some surveys have shown that such neighborhoods have lower property values than surrounding areas, and residents have been the target of racial taunts and graffiti. But the modern locations of the old villages are largely unknown to the general public, and many burakumin prefer it that way.

Google Earth's maps pinpointed several such areas. One village in Tokyo was clearly labeled "eta," a now strongly derogatory word for burakumin that literally means "filthy mass." A single click showed the streets and buildings that are currently in the same area.