The unnamed actor shared a picture of a bag filled with fake marijuana from the set of new comedy Neighbors 2: Sorority House, and added the caption, "Thanks for the weed Zac Efron! BTW (by the way) it's only a prop, people."

However, the social media post landed the extra in trouble with producers and he was fired with immediate effect, according to TMZ.com.

Efron is not thought to have been involved in the decision to let the actor go, but the extra has reportedly been in trouble before over posting inappropriate things on social media during filming.

The drug reference emerges two years after the High School Musical hunk battled addiction issues in rehab. He subsequently revealed cocaine and alcohol had led to his demise.

Neighbors 2: Sorority House, the sequel to Efron and Seth Rogen's 2014 comedy Bad Neighbors, is due for release next year (16).

A representative for Efron has yet to comment on the report.