Japanese seasoning maker Ajinomoto has been ordered to pay US$1.7m to a former employee, who claimed he helped develop the low-calorie sweetener aspartame.

Masayoshi Naruse filed a lawsuit against Ajinomoto in 2002, claiming the company paid him too little for discovering how to mass produce the sweetener, which is sold as Pal Sweet in Japan and NutraSweet and Equal elsewhere. Naruse claimed Ajinomoto had earned around ¥29.6bn from aspartame and that he should be entitled to ¥2.0bn, reported Agence France Presse.

However, the High Court in Tokyo ruled that Ajinomoto had earned just ¥7.9bn from aspartame, and that Naruse was entitled to ¥189.4m (US$1.7m) of that.

Ajinomoto obtained a patent on the production method in Japan in 1988 and in the US in 1992.