Seoul, Aug 12 (IANS): South Korea will ban social media influencers from pitching a new product or service on their online platforms without disclosing their business ties with corporate sponsors from next month, the country's antitrust watchdog said on Wednesday.

The move comes amid controversy over some famous social media influencers' involvement in what is called "backdoor online advertising," Yonhap news agency reported.

South Korea's antitrust watchdog, the Fair Trade Commission (FTC), said its revised advertising guidelines for social media platforms will become effective starting September.

The new rules require influencers on social media platforms, such as YouTube or Instagram, to state clearly whether their product endorsements are "financially rewarded or intended for promotion."

Vague wording like "thanks to" or "reviewer group" will be prohibited on their videos as well, said the report.

The corporate watchdog said it will start to crack down on and punish violators after a certain guidance period.

Violators -- both influencers and corporate sponsors -- will be slapped with a fine of up to two per cent of related sales and revenue or $422,000.