A Waikato woman has admitted multiple charges for supplying and possessing methamphetamine (P) and Gamma-Butyrolactone (GBL).

Sharon Marfell, 49, was a high-ranking member of a drug syndicate responsible for supplying methamphetamine.

She was also involved in "debt collection" of money owed to her for drugs.

At least one dealer who assisted Marfell referred to her as the boss while another also sold drugs Marfell supplied.

Marfell was arrested on November 12, 2020.

Between October 2019 and November 2020 she was involved in supplying 540 grams of P.

She supplied 40 millilitres of liquid ecstasy over five occasions and offered to supply as much as 2000ml.

Overall Marfell had officially supplied 664g of P.

A search of her home uncovered nine 1-litre bottles of GBL as well as two 5-litre plastic fuel cans that had GBL residue.

Appearing before Justice Graham Lang via audio-visual link in the High Court at Hamilton today, Marfell admitted possessing of P for supply and supplying P, participating in an organised criminal group, conspiring to deal methamphetamine and possessing and supplying GBL.

Justice Lang convicted Marfell - who choked back tears as she pleaded guilty to the 12 charges - and remanded her in custody for sentencing in September.

- Natalie Akoorie, Open Justice