Because Mr Naitoko did not have a will, his mother Ivoni Fuimaono would have to obtain "letters of administration" from the court to act on his behalf.
"The family are in a very financially difficult situation and the ministry of Justice through the Legal Services Agency has even gone to the extent of granting legal aid to apply for letters of administration, which is quite unusual," Mr Pidgeon said.
"To bring this claim, we had to satisfy [the ministry] that there were good prospects of success before it was granted. They've accepted that she's [Ms Fuimaono] not in a position to apply for letters of administration."
Mr Pidgeon said Ms Fuimaono has a strong case.
He said the Independent Police Conduct Authority had pointed out "serious dereliction of duties" by the officers involved.
"... she feels unless she seeks compensation, justice will not be done."
He said the family was very relieved to have been granted legal aid.