Sniffer dogs could soon be used at AFL matches in a bid to crack down on violent behaviour and illicit drugs at games.

But the AFL Fans Association says alcohol remains the primary cause of poor crowd behaviour.

In the stadium's annual report MCG Trust chairman Steve Bracks said illicit drugs were a major contributing factor behind violent incidents and current screening processes were falling short.

"Often poor behaviours are influenced by the use of illicit drugs which are very hard to detect in our entry screening procedures.

"The Club continues to work with our security contractor and Victoria Police to improve our capacity to manage these incidents and, where possible, to reduce the incidence of them."