PureCircle's stevia imports released by the US

The company said that it will “work actively with the CBP to effect a full resolution of the issue for further shipments”.

The company’s stevia imports were seized on 2 June by the CBP as they had received information that the goods were allegedly made by slave labour.

It was the latest company to be targeted by the trade facilitation and trade enforcement act of 2015 which was signed into law in February. It prohibits imports of goods produced by forced labour into the US.

In a statement at the initial seizure of the goods, PureCircle disputed the allegation and said the company had provided documentation that it had not worked with Inner Mongolia Hengzheng Group Baoanzhao Agricultural and Trade, which was also named in the complaint by the CBP.

The company said it was committed to human rights and was certified by the Sedex Members Ethical Trade Audit, an independent auditor, which states that no forced, bonded or involuntary prison labour was used.

A PureCircle spokesperson said at on 2 June: "We have an explicit policy prohibiting use of prison or forced labour in any part of our business."

Stevia is a plant extract that is used as a sweetener in several food and drinks including Coke Life, Pepsi True and PureVia.

PureCircle’s shares were up 12.96% to 305p at 0925 BST.