SAN FRANCISCO -- San Francisco's city attorney is demanding that Justin Bieber's music publisher help determine who is responsible for sidewalk graffiti promoting the pop star's latest album.

City attorney Dennis Herrera sent a letter to Universal Music Group on Monday, saying the graffiti appears to have been applied with spray paint that has not come off even after recent rainstorms. That contrasts with other recent sidewalk marketing campaigns that have used chalk, according to Herrera.

Herrera said public works crews have removed some of the graffiti at great expense, although he did not provide a figure. The city attorney's office released photographs of eight instances of the graffiti and asked for Universal's help in determining its full scope.

Emails seeking comment from representatives of Universal Music Group were not immediately returned.

The graffiti promoting Bieber's new album, "Purpose," has been found in Haight-Ashbury and other neighborhoods. City officials have received complaints about it, Herrera said.

"This prohibited marketing practice illegally exploits our city's walkable neighborhoods and robust tourism, intentionally creates visual distractions that pose risks to pedestrians on busy rights of way, and irresponsibly tells our youth that likeminded lawlessness and contempt for public property are condoned and encouraged by its beneficiaries," Herrera said in his letter.

Herrera's office previously went after a 2010 marketing campaign that glued decals of fake $25,000 bills to city sidewalks to promote an online game. An advertising agency agreed to pay the city a $45,000 penalty for the decals.