The group's head, Martin Sellner, has confirmed he exchanged emails with the man but denies involvement in the attack.
The accused gunman faces 50 murder charges and 39 attempted murder charges. He appeared in the High Court at Christchurch this morning.
Around 50 family members of the mosque attack victims filed into the courtroom to watch the proceedings.
There were also more than two dozen reporters from New Zealand and around the world, along with eight police officers and several security staff.
German police said the accused shooter used his credit card last November to pay for a ticket to Neuschwanstein Castle — a popular tourist destination near the Austrian border commissioned by Ludwig II of Bavaria in the 19th century.
At the time, the now 28-year-old was traveling around Europe with stops including Austria, Hungary, Romania, Bulgaria and Estonia.
The accused in 2014 also made a payment to a German living in the southwestern state of Baden-Wuerttemberg, police said. It was unclear what the purpose of the payment was. Federal police said their investigation is ongoing.
- AP with NZ Herald