Donghua Liu's long quest for life in NZ

It was a long and rocky road for Chinese businessman Donghua Liu as he tried to establish himself in New Zealand.

Donghua Liu in the Auckland District Court. Source: 1 NEWS

And years later those efforts are having a big political impact on both National and Labour.

Now political turmoil is swirling around with revelations Labour leader David Cunliffe intervened in his residency application back in 2003.

Mr Liu first applied for New Zealand residency in August 2002. Three years later, it was granted against official advice by Labour's associate immigration minister, Damien O'Connor.

Over the years, Mr Liu has donated to both major political parties, including a $15,000 donation to Labour and a $22,000 donation to National.

Three years ago, Prime Minister John Key joined Mr Liu at the opening of his $70 million construction project in Newmarket in Auckland which now appears to be on hold indefinitely.

Earlier this year, Maurice Williamson resigned his Cabinet positions following the revelation that he contacted a top ranking police officer after Donghua Liu was arrested on domestic violence charges.

Mr Liu pleaded guilty to two charges of domestic violence in April and is due to be sentenced in August.