The man charged with vandalising a memorial for comedian Eurydice Dixon says he did so because he believed vaccines caused the autism of her accused killer.

Police found offensive paint markings on the field at Princes Park in Melbourne's inner north on June 18, hours before 10,000 people gathered at the park for a vigil in Ms Dixon's honour.

In a post on Facebook, Andy Nolch admitted to carrying out the graffiti, and referred to the fact that Ms Dixon's accused killer, 19-year-old Broadmeadows man Jaymes Todd, had been diagnosed with autism spectrum disorder.

The post was sent late on Wednesday night. ( Facebook: Andy Nolch )

Australia's chief medical officer, Brendan Murphy, last year said research that suggested a possible link between vaccines and autism was "completely false and has been debunked".

Firefighters had to remove some of the graffiti with a high pressure hose. ( AAP: Ellen Smith )

Mr Nolch, of Bulleen in Melbourne's east, was last week charged with criminal damage, offensive behaviour and making offensive graffiti.

Ms Dixon was found by a passer-by on a sports field in the early hours of June 13 after she walked home from a comedy gig.

Paramedics were called to the scene but Ms Dixon could not be revived.

A meme posted to Andy Nolch's Facebook page a few days after Ms Dixon's death. ( Facebook: Andy Nolch )

Mr Todd has been charged with Ms Dixon's rape and murder.

His lawyer, John Riordan, told Melbourne Magistrates' Court his client had been diagnosed with autism spectrum disorder.

In the days following Ms Dixon's death, Mr Nolch made several Facebook posts in which he criticised media coverage of the case.

"The mainstream media is only reporting on murders done by men, which is making people think that all men are crazy scary murderers," he posted on June 18.

Eurydice Dixon was walking home from a comedy gig when she was attacked. ( Supplied: Facebook )

Mr Nolch said on social media that he once hosted a comedy show on community television and "used to be interested in stand up comedy", but did not describe himself as a comedian.

"I do not want to be associated with Melbourne comedians," he said.

"The TV show never got cancelled, I stopped making it as I discovered that TV is full of corporate and government propaganda."

The ABC has contacted Mr Nolch for comment.