Ms Christina is not required to appear in court but prosecutors were seeking her cooperation via the German embassy.
Wackrow has chosen to defend himself, but will be aided by a translator.
He was originally wanted in relation to a theft.
Wackrow was arrested in September at Bali's airport as he headed for Australia, where he had reportedly been living in Burleigh Heads, on Queensland's Gold Coast.
Police had alleged he had a surfboard with him that was stolen from an American woman whom Wackrow had stayed with in June.
In August, the woman complained to police that Wackrow threatened to kill and "damage her face" in a SMS message.
He was accused of stealing a surfboard, mobile phone, two watches and money from her Canggu villa - but the charges were dropped due to a lack of evidence.
He is one of several Kiwis in trouble with the law in southeast Asia.
Antony de Malmanche, a 52-year-old pensioner from Wanganui, was arrested in Bali in December, allegedly with 1.7kg of crystal meth in his backpack.
Peter Gardner, 25, was detained in China in November and could face execution by firing squad after his luggage was apparently found to contain meth.
His Australian girlfriend Kalynda Davis, 22, was detained at first, but released.
In Thailand, New Zealander Taylor Grainger, 41, was arrested in December with methamphetamine and cocaine in a police blitz of the tourist centre of Phuket.
- AAP
