NSW parliament's longest serving MP and leading morals campaigner, the Christian Democrat elder Reverend Fred Nile, has failed to properly declare his business interests and positions in associations for at least 10 years, a Herald analysis reveals.

The pecuniary interest disclosures of Mr Nile, which are required by law to be updated each year, are inaccurate and inconsistent, the analysis shows.

Reverend Fred Nile's pecuniary interest disclosures are inaccurate. Credit:Jon Reid

Mr Nile, the leader of the Christian Democratic Party (CDP), is the sole shareholder, director and secretary of Family World News, which was created in 1994 and produces a monthly publication by the same name, according to ASIC documents.

But he did not declare he held an interest and positions in the Family World News company until 2014-15 and 2016-17, under "part five: interests and positions in corporations". In the year between, he omitted any reference to it.