"Further arrests and charges by police are also possible."
Christchurch District Court heard on Wednesday that a male driver in his 50s has been charged with conspiring with another person to manipulate a race result earlier this year by "administering a substance" to a horse before the race "in order to gain a pecuniary advantage, namely the winning stakes".
Defence lawyer Phil Shamy said the man denied the charge and would elect trial by jury.
Judge Raoul Neave granted him interim name suppression which will be reviewed when he comes back to court – along with others charged over Operation Inca – on March 25 next year.
North Canterbury trainer Andrew Douglas Stuart, 42, who has previously entered not guilty pleas to three race-fixing allegations, faces a fourth fixing charge.
It's alleged that with another man he "manipulated the overall result" of a race earlier this year by deception and without claim of right.
A 40-year-old Canterbury man who denies three race-fixing charges and who is yet to enter pleas on two unrelated drugs charges had another drugs charge laid this week.
Graham Henry Beirne, a 71-year-old Christchurch man, previously denied two race fixing charges, and faces a third charge.
Defence counsel Richard Raymond QC asked for no plea to be entered on the new charge, and Judge Neave remanded him until March 25.
Three other men – aged 50, 35 and 26 – deny race-fixing allegations, as does Palmerston North man Brent Stephen Wall, 47, and 44-year-old Rolleston-based horse trainer Nigel Raymond McGrath.
Others face drugs charges that their lawyers say is unconnected to the horse racing investigation, including Elie Sawma, a 42-year-old Christchurch hairdresser charged with supplying the Class B controlled drug MDMA, possession of MDMA, and offering to supply the Class A drug cocaine.
Another accused, who cannot be identified for legal reasons, is yet to enter pleas.
Some of the accused were remanded by Judge Raoul Neave to a Crown case review hearing on March 25 next year, while others will be back in court on January 29.