In a circular, the SPP instructed officials to increase the number of investigations and pay close attention to the legality of celebrity endorsements.
China updated its advertising laws for the first time since 1994 in September 2015, amid government concerns that the existing regulations didn't adequately protect consumers.
A key area of focus for regulators was celebrity endorsements — one of the most common marketing methods in the country.
In order to crack down on unscrupulous claims, the new law stated that celebrity endorsers can be held responsible for false claims in ads, while child celebrities under the age of 10 cannot endorse products at all.
Tighter rules specifically for food and supplement adverts were also introduced. For the latter, brands were barred from making claims guaranteeing the product's safety, or that it can prevent diseases. Furthermore, marketing claims such as "the most advanced", "best", and "the latest science" were prohibited.
For conventional food products, an advert were disallowed from carrying any health claim around the product or an individual ingredient, or carry endorsements from medical institutions or a consumer.
Australian supplement firm Blackmores was one of the first to run afoul of the new rules, amid initial confusion about when they would be enforced.
Blackmores said the fine was related to marketing materials displayed at a pop-up store at Shanghai's Pudong airport in 2016, and used in international campaigns.
The company said: "At the time, there were uncertainties in the market about the new advertising law, and we were unaware that the language used was no longer allowed."
Nike and Japanese retailer Muji were also publicly named for breaching the rules, in an announcement timed to coincide with China's Consumer Rights Day last March.
Muji came under fire for allegedly selling food and beverage from Tokyo, one of 10 prefectures in Japan that were banned from exporting to China after the Fukushima disaster.
This latest edict from the SPP suggests that more brand violations will be highlighted this year, with investigators under clear instructions to better enforce the rules.
A statement published by state-run press agency Xinhua said officials should increase information-sharing with government agencies, search the media for breaches, and encourage tip-offs from informers.
"If the watchdogs fail in their responsibilities, procuratorates should not hesitate to initiate litigation," it said.
Xinhua added the order is in response to controversies involving the advertising of foods, supplements and drugs targeting "gullible, elderly or rural consumers".
Last week, we revealed that China topped the list of media scandals involving food and beverage firms in 2017, with the overwhelming majority due to regulatory breaches.