Vietnamese authorities have arrested a beauty queen and social media influencer for consumer fraud after she promoted a counterfeit fibre supplement.

Nguyen Thuc Thuy Tien had heavily marketed gummies said to be rich in fibre on her social media channels.

But a public backlash erupted after product tests revealed this was untrue.

A former winner of the Miss Grand International beauty competition, Ms Nguyen is a well-known personality in Vietnam and previously received accolades from the government.

Ms Nguyen had promoted Kera Supergreens Gummies along with social media influencers, Pham Quang Linh and Hang Du Muc.

Investigators said the product was the result of a joint venture between Ms Nguyen and a company set up by the two other influencers.

The influencers claimed that each of their gummies contained fibre equivalent to a plate of vegetables.

A member of the public sent the product for testing at a lab, which found that each gummy only contained 16mg of fibre, far from 200mg as claimed.

Authorities then launched an investigation, which found that sub-standard ingredients that were low in fibre were used in the manufacture of the gummies.

The product's packaging also did not state the fibre content, nor did it state that the product contained a high level of sorbitol, which is used in laxatives.

The three influencers were fined in March, and apologised to the public.

The following month, Vietnamese authorities arrested Mr Pham and Hang Du Muc as well as officials from their company and the gummies' manufacturer.

They were charged with producing counterfeit goods and defrauding customers.

On Monday, authorities announced the arrest of Ms Nguyen for allegedly deceiving customers.

More than 100,000 boxes of the gummies were reportedly sold before sales were halted due to the scandal.

After winning the Bangkok-based beauty pageant in 2021, Ms Nguyen became a celebrity sought after by many Vietnamese brands, and appeared on several reality TV shows.

She also received certificates of merit from the prime minister and the Ho Chi Minh Communist Youth Union under Vietnam's ruling Communist Party.