Charlie Hebdo top cartoonist Renald Luzier to leave newspaper

French satirical weekly Charlie Hebdo is facing new problems, with a top cartoonist leaving because of the emotional burden after extremists killed his colleagues, and divisions over how to use donations from around the world.

Cartoonist Renald Luzier, also known as Luz,who drew the newspaper's first cover after the Jan. 7 attack killed 12 people, said in an interview Tuesday in the daily Liberation that each issue is "torture, because the others are no longer there." He will leave in September.

He also says he will no longer draw the Prophet Muhammad. Charlie Hebdo was criticized for its prophet drawings.

Meanwhile, the long-struggling paper's editorial staff and management disagree over the 4.3 million euros ($5.9 million Cdn)in donations received since January. The editor and publisher said a special commission will determine how to use it.