Convicted killer Graeme Burton has so far received more than $12,000 in legal aid so that he could defend a charge of attempted murder.
A fortnight ago, Burton was found guilty of attempting to murder a fellow inmate at Auckland Prison last December.
Attorney-General Chris Finlayson told Parliament on Thursday that the legal services agency paid $12,342.50 in lawyer's fees and other costs for Burton's defence.
But because Burton is still to be sentenced, Mr Finlayson said, the final cost is not yet known.
Burton is serving a life sentence with a non-parole period of 26 years for the murder of Karl Kuchenbecker in 2007 while on parole.
He previously served 14 years of a life sentence for the murder of Paul Anderson in 1992.