Insults towards the coach and president of Marseille were found scrawled across the walls of the troubled club's training ground on Friday.
Interim boss Jose Anigo and president Vincent Labrune have been targeted by disgruntled fans as OM languish in sixth place in the Ligue 1 table, 12 points adrift of the Champions League qualifying places with just seven games of the season remaining.
"Labrune dirty Parisian" and "Anigo, corrupt, bandit, get lost, you and your henchmen" were daubed on the walls of the club's training complex, according to a picture published on the website of local daily La Provence.
Meanwhile, groups of unhappy supporters have called to boycott Friday evening's home meeting with bottom club Ajaccio following a desperate run of just two points from five league games in March that has jeopardised their chances of even qualifying for the Europa League.
Anigo has already said that he will stand down at the end of the season to make way for a new coach, although he is expected to carry on in the role of sporting director.