The rules were not as strict in February 2009 when Robin Newton made his last payment to his daughter Emma, but it is arguable he still should have declared it.
He paid her out of his £71,378 office cost expenditure, some of which also went to his wife and son.
At that stage the rules stated "it is a cardinal principle that Members are responsible for making a full disclosure of their own interests in the register; and if they have relevant interests which do not fall clearly into one or other of the specified categories, they will nonetheless be expected to register them".
Later that year, after the MPs' expenses scandal at Westminster, it was made explicit that declarations should cover family members. The new code said that individual MLAs "should register family members who benefit directly or indirectly in any way from any office cost expenditure (e.g. through employment or through the rental of office accommodation)."
At this stage, Mr Newton declared payments to his wife and son, but payments to his daughter had ceased.
Very strict standards apply at Westminster. There, the political career of Derek Conway, the Tory MP for Bexley and Sidcup, was cut short even under the more permissive rule that applied before the MPs' expenses scandal.
In January 2008 he announced that he would not seek re-election after it was revealed that he had paid a salary to his son Freddie, who was a full-time student at Newcastle University, as a political researcher using public funds. There being no record of his son doing any work at Westminster, David Cameron also withdrew the whip, effectively expelling Mr Conway from the Conservative parliamentary party.
In Mr Newton's case no salary was involved, only occasional payments for research services.
We currently lack any independent body to set the precise boundaries by monitoring, reporting and making recommendations on issues relating to standards in public life.
Under policy adopted earlier this year, the CSPL can no longer intervene in Northern Ireland or Scotland unless specifically invited to do so by the local authorities.
The Scottish Parliament has set up its own body to fill the gap and, earlier this month, Lord Bew called on Stormont to do the same.
CPSL recommends that no relatives be employed by MPs as a matter of best practice. However, a compromise was reached whereby they are allowed to employ one relative provided they declare it.
Robin Newton's case may increase the pressure for the CSPL to be called in to give MLAs clear guidance on what constitutes ethical behaviour.
In the longer term we need to establish our own independent body to spell out best practice for both MLAs and others paid from public funds and to monitor compliance.
Without scrutiny and transparency, politicians won't be trusted by the people whose votes they need.