A security breach has caused early morning disruption at Melbourne Airport, delaying flights as passengers were forced to be rescreened at security checkpoints.

According to a Qantas spokesperson, a passenger arrived in Melbourne from Perth this morning, where he had been screened on departure.

However, instead of proceeding directly to his connecting flight he exited the sterile area of the terminal and made his way towards the baggage carousel.

The man was in the baggage area for less than a minute, before walking back through one-way security doors the wrong way and triggering an alarm.

As security were initially unable to locate the man, a decision was made to clear the airport and rescreen all passengers.

The passenger was subsequently found and was interviewed by the AFP, who are not laying charges.

Melbourne Airport's incident is unrelated to a security breach at Adelaide Airport this morning that also sparked chaos.

Tim Joyce was sitting on his plane waiting to take-off when he was told to disembark.

"We were a minute away from taking off. And they took us all off the plane. There's thousands of people out here waiting," Mr Joyce told ABC News Breakfast. 

"Every single person that has been through screening, including staff, were told to leave the terminal and go back to be rescreened."

Melbourne Airport said in a tweet after 7:30am that screening of passengers in terminal one had resumed, but delays should be expected.