The Department of Immigration and Border Protection has launched a search for conductive energy weapons, otherwise known as stun guns.
According to a tender document, the department intends to use the weapons to establish "training and deployment capabilities" for immigration and customs officers.
A spokeswoman for the department said stun guns were not currently used by staff and there was no immediate plan to acquire them.
"The department continually explores options to improve the personal defence equipment carried by some Australian Border Force officers to reduce the reliance on lethal forms of self-defence," she said.
Greens Senator Sarah Hanson-Young said the proposal was another example of the government's "obsessive militarisation of the immigration department".
"First they bought new uniforms and guns, then they said officers would stop and search random people in the streets and now they want tasers," she said.
"Border Force are out of control. Will these tasers be used on everyday Australians, will they be used on people seeking asylum? The Immigration Minister has to clarify why on earth his department needs these weapons."
A spokeswoman for the department said "personal defence equipment" was only carried by a small number of trained border force staff and only used for self-defence or to prevent the loss of life.
She said the protocols were consistent with practices followed by law enforcement agencies.
At a senate estimates hearing last year, Australian Border Force Commissioner Roman Quaedvlieg said the number of firearms used by the force had increased and would continue to in coming years.
"It is the intent to increase the number of officers who are able to use force up to and including lethal, however we need to go through an assessment in terms of functions," he said.
"Where we make a judgement that a function ought to be conducted by an armed officer, no person without a formal qualification will be able to take up those positions."
He admitted the notion of officers carrying firearms was "alien to part of the department that didn't hitherto have an exposure to that".
"I wouldn't want to see ABF officers carrying firearms when there is actually no need for them to require firearms because their interface with the public does much beyond the need to use force.
"Having said that, we need to recognise that there are functions and situations that will occur in our operation environment where our officers need to be able to protect themselves and others."