San Francisco demands help investigating Bieber graffiti

San Francisco's city attorney is demanding Justin Bieber's music publisher help determine who was behind sidewalk graffiti promoting the pop star's latest album.

City attorney Dennis Herrera sent a letter Monday to Universal Music Group, saying the Bieber graffiti appears to have been applied with spray paint that has not come off even after recent rain storms.

Herrera said other recent sidewalk marketing campaigns used chalk.

Herrera said public works crews have responded to remove some of the graffiti at great expense, although he did not provide a figure.

Emails to Universal Music Group representatives were not immediately returned.

The graffiti promotes Bieber's new album, "Purpose," and has been found in Haight-Ashbury and other neighborhoods.

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