His arrest embarrassed several MPs as it was revealed Yan was granted New Zealand citizenship in August 2008 after then-Associate Immigration Minister Shane Jones ignored advice from Internal Affairs officials, who wanted the businessman's request declined.
The decision fell to Jones because Cabinet colleague Rick Barker - who should have made the decision - was an acquaintance of Yan. Yan's citizenship application also included letters of support from former MPs Chris Carter, Dover Samuels and Pansy Wong.
Yan, considered a political opponent of the Chinese Government, was wanted in his homeland for an alleged fraud of several million dollars.
The Herald on Sunday understands there is still an arrest warrant for Yan in China.
Johnstone said the eight charges were withdrawn because of the length of the trial and the Crown was not assured its intended witnesses from China would be in New Zealand when required to give evidence.
"Without those witnesses, the Crown was unlikely to be in a position to prove beyond reasonable doubt a key allegation required for a conviction on the eight counts."
Johnstone would not elaborate on the key allegation.
The credibility of witnesses in the case was questioned during an earlier court hearing, amid fears of pressure from the Chinese Government.
Yan is represented by David Jones, QC, and Paul Wicks.