''We are in a war'' declared Customs chief Mike Pezzullo on Wednesday, as he stood alongside Immigration Minister Scott Morrison to unveil an $88 million upgrade to the screening and inspection of international mail and cargo arrivals.

''In a war, you need weapons, you need bullets.'' The ''war'', he explained, was against crime syndicates and the ''bullets'' were enhanced resources for the customs service, which will take the form of new dog teams, mobile X-ray technology to allow for covert screening of suspect items, an expanded intelligence unit and a greater number of inspections of mail and cargo items.

Mr Morrison said the $88 million package was ''real money'', delivering on a promise made by the coalition in the lead up to the election.

New ''war'' measures will include $30 million to expand examination of international mail - rising from 40 million to 50 million items a year - while inspections of air cargo will rise from 1.5 million to 2 million a year. An additional 1500 sea containers a year will also be inspected, while 15 extra dog detector teams will be formed, and eight new officers appointed to the intelligence unit.

Mr Morrison said an additional investigation squad would be formed to target firearm and drug traffickers.

Mr Pezzullo said deployment of new mobile x-ray units would ''surprise our enemies at times of our choosing''.

While inspections of air cargo would still cover only 6 per cent of arrivals, he said the choice of targets would be driven by intelligence assessments.

Responding to questions about corruption, Mr Pezzullo said eight customs officers had been arrested in the year to November, most in relation to Operation Heritage, which had investigated a ring of corrupt officers and co-workers at Sydney Airport.

''We have since had cause to arrest a number of officers for other causes, those matters are ongoing'' he said. But he said the culture was changing inside customs. ''People are confident to come forward and actually provide intelligence leads on what some, not many, a few of their co-workers are up to.''

An investigation of the corrupt ring at Sydney Airport conducted by Integrity Commissioner Philip Moss last year found that it had operated between 2007 and 2012 and grown out of '' a weak integrity culture and changes in the risk environment''.

This had allowed a number of individuals to ''move from enabling each other's friends to exceed duty-free limits when arriving on overseas flights [in 2007] to an orchestrated importation of steroids and pseudoephedrine'', Mr Moss found.