Nauru Air Boeing 737-300 VH-NLK came through Cairns twice yesterday.
The first was in the morning from Darwin (YPDN). Unfortunately I do not know the Flight Number. It then continued on to Nauru (ANYN) as ASY999.
Later that afternoon, NLK returned from Nauru (ANYN) using ASY999 as the Flight Number. Then during the evening the 737-300 departed for Darwin (YPDN) as ASY999.
Below are shots of it departing in the evening for Darwin: