LOS ANGELES, Sept. 4 (Xinhua) -- Bill Cosby' s star on the Hollywood Walk of Fame was vandalized Tuesday morning with the words "serial rapist" scrawled in black marker.

According to the report of Los Angeles Times, the Los Angeles Police Department heard that the incident occurred at about 5:30 a.m. Tuesday and detectives were investigating the case.

The words have been scrubbed, but no arrests have been made.

It is the second time that Cosby's pink star was vandalized in four years. In 2014, the word "rapist" was also written on it.

The 81-year-old Cosby is a former U.S. comic legend and convicted sex offender. About 60 women have accused him of sexual abuse since 2014.

He was found guilty at an April retrial of drugging and sexually assaulting former Temple University staffer Andrea Constand in his Pennsylvania home in 2004. He is expected to be sentenced Sept. 24 and faces up to 30 years in prison.

Cosby was awarded two times of Golden Global, four times of Emmy and nine times of Grammy in his career.