A Malaysian woman who said she was subjected to sex up to 35 times a week spiked her New Zealand fiance's drinks to "slow him down," a court in Auckland was told today.

But Ng Mee Kwan, 41, walked free when the court ruled there was insufficient evidence to prove a charge of administering a poison with intent to cause inconvenience to 53-year-old Martin Walker.

According to police, former air stewardess Ng crushed antihistamine and anti-inflammatory medicines which she put in her fiance's vodka and orange and his wine.

She later added crushed pet repellent to the other medicines which she put in a meal of fried rice.

'Extraordinary' sexual demands

When interviewed by police, Ng admitted drugging Walker's food and drink to "slow him down".

Walker, now Ng's former partner, denied he demanded sex with "extraordinary frequency" but admitted his sexual demands had caused problems in their relationship.

He accepted Ng was not trying to cause him significant harm but was "probably trying to dampen my romantic and sexual ardour".

Ng's lawyer Michael Corry said outside the court that Ng "just got to the end of her tether and she was trying to introduce medication which would make him drowsy, which would in turn reduce the level of demand for sexual relations."