The Commonwealth Ombudsman has produced two scathing reports on practices by Australian immigration authorities.

The number of people deported from Australia because of serious criminal convictions has increased more than tenfold since 2014, with a huge spike in the number of New Zealanders being sent home - one of two scathing ombudsman's reports on Monday on practices by Australian immigration authorities.

A spokeswoman for Immigration Minister Peter Dutton said the government made no apologies for strengthening deportation laws "to further protect the Australian community". Credit:Alex Ellinghausen

The review of section 501 of the Migration Act considered the treatment of people who have their Australian visas cancelled because of crimes resulting in more than 12 months' imprisonment, finding the number of visas cancelled shot up from 76 in 2013-14 to 983 in the last financial year.

Of the 1219 non-citizens who had their visas cancelled between January 2014 and February 2016, 697 were from New Zealand and 124 were from Britain, many of whom have been in Australia since childhood.