I still remember the damning verdict of ITI Tropicals’ Gert van Manen, when I spoke to him for my investigation into the coconut water market last year: “We tried to get the attention of the retailers and regulators, but they have bigger fish to fry. It’s not a safety issue, but the consumer is being cheated.”

Van Manen is arguably the original whistleblower on the coconut water boom. He saw rapidly rising global sales, opaque supply chains and intensely sweet drinks with squeaky clean labels, and concluded: something can’t be right.

Lab tests on coconut water brands in the US confirmed his suspicion; undeclared added sugar in these supposedly pure and 100% natural drinks was rife. Yet when van Manen tried to raise the alarm, he found very little appetite to take action.

That’s why it is so pleasing to see the UK’s Food Standards Agency, through its National Food Crime Unit, take the issue seriously. As we reveal this week (p4), a probe it ran earlier this year uncovered widespread problems with undeclared added sugar in coconut water imported into the UK.

Added sugar was precisely the issue we flagged up in our investigation in August 2016, which also revealed growing concerns among UK brands and explained why the sector - with its complex supply chains, colourful ‘health’ claims and bewildering number of brands - is so vulnerable.

The FSA’s crackdown will do much to hold the sector to higher standards. Several brands caught up in the probe tell us they have re-audited their supply base and introduced new testing regimes. But while brands must make sure their products are as described on the label, retailers also have an important role to play in protecting consumers by robustly vetting brands. Moreover, the lack of an agreed compositional standard for coconut water must be addressed with some urgency. Regulatory efforts will ultimately fail if testing is undermined by disagreements over standards and protocols - either because potential transgressions are not caught or because brands are being implicated unfairly.

Read in full: The Grocer’s 2016 investigation into coconut water 

Coconut water is one of grocery’s outstanding success stories. Retailers, regulators and brands must now work together to protect that.