The Australian Federal Police (AFP) has boosted anti-terrorism security at Brisbane's international and domestic airports.

The AFP will be joined by 25 former state police officers and have begun patrolling the Brisbane airports today.

By May next year, 56 new officers are expected to be on patrol.

Brisbane Airport police commander Steve Grant says they will perform a range of general policing and intelligence tasks.

"There is no imminent threat, there is always the threat of terrorism, that is an international threat," he said.

"Australia is appropriately putting into place a tiered approach to counter-terrorism and that necessarily involves policing."