Prime Minister Malcolm Turnbull is referring "a number of matters relating to citizenship and the operation of section 44 of the constitution" to the parliamentary committee that looks at electoral matters.

"Australia is the most successful multicultural society in the world and around a half of our citizens were either born overseas or have a parent born overseas. These Australians may be citizens of another country and, as we have seen with several members and senators, not be aware of it," Mr Turnbull said in a statement.

The committee has been asked "to examine how our electoral laws can be improved to minimise the risk of candidates being found to be ineligible in the future and what, if any, changes should be made to section 44 (i) of the constitution".

Mr Turnbull says people "expect us to resolve the citizenship issue once and for all" and the inquiry "will help us ensure similar issues do not affect future parliaments".