Under the terms of this deal, Lopez agreed not to promote the sale of any product containing resveratrol in any media for four months or on the radio for six months.
However, About Health and King claim Lopez induced this agreement by making false representations, according to a judgement from Justice Murray Gilbert this month on a series of pre-trial applications.
The pair have issued High Court proceedings against Lopez, LaniLopez.com Ltd and Healthy Insight Ltd - the company that operates the LaniLopez.com website. The case is due to be heard in court in October.
The plaintiffs allege the defendants carried on their new business in breach of the agreement between Lopez and King and in a manner that is unlawful, Justice Gilbert's decision said.
The allegations in the case include breaches of the Fair Trading Act, of the Trademarks Act, and misuse of confidential information, Justice Gilbert's decision said.
As well as this, it is alleged Lopez unlawfully interfered with the relationship between About Health and The Radio Network.
According to Justice Gilbert's decision, King and About Health want a "permanent injunction restraining the defendants from carrying on the business in the allegedly unlawful manner".
They are also seeking damages to compensate About Health for lost sales.
Lopez's lawyer told the Herald the case was being defended but declined to comment further.
The action is not the first time Lopez and King have been in a court dispute.
Last year King brought a private prosecution against Lopez in the Auckland District Court.
In this case, Lopez pleaded guilty to one charge of dishonestly using a document and another of dishonestly using $2134.
According to Judge Emma Aitken's sentencing notes, the bank transferred the $2000 at Lopez's request from an About Health company account to her daughter's account.
The money was paid back shortly after the private prosecution was commenced and in November, Lopez was discharged without conviction on both counts she had pleaded guilty to.
