A United Nations agency has launched an investigation into claims that a key consultation into how much sugar we should be eating was secretly funded by the sugar industry.
The consultation was meant to look at whether sugar was bad for health
The BBC's Panorama programme has uncovered documents which reveal the World Sugar Research Organisation and International Life Sciences Institute, both funded by the sugar industry, helped pay for the Expert Consultation on Carbohydrates in Human Nutrition.
The programme also reveals that ISLI was given the opportunity to suggest members of the committee and select the chairman, as well as review the agenda of the consultation.
Since its publication the report of the consultation has been used by the sugar lobby to fight any suggestion of a link between sugar and health concerns.
Now the UN's Food and Agriculture Organization (FAO) has said it plans to reconvene the research committee "urgently".
The expert consultation was a joint venture between the World Health Organisation (WHO) and the FAO and was due to look impartially at key questions, including whether sugar is detrimental to human health.
But Jim Mann - a highly respected nutritionist from New Zealand - told the programme he always had doubts about the consultation's independence.
He said: "When we arrived some of us were summoned by one of the officials who was involved in the organisation of the consultation and told very clearly that it would be inappropriate us to say anything bad about sugar in relation to human health."
Another of the team invited to Rome sensed that the science might not be the only driving force.
Professor John Cummings claims that a chairman had already been chosen before the committee began its work.
He also claimed that one official - there as an observer - obstructed the debate when sugar was being discussed.
He added: "I was very surprised when he sort of came immediately to the defence of sugar during the consultation. I couldn't really understand why he did because normally these officials sit and listen and just sort of prod you when they think something needs doing but this was quite amazing."
The experts didn't know that the sugar industry was paying for them to be in Rome.
But Panorama has discovered a series of documents which show exactly where the money came from.
It shows that the World Sugar Research Organisation - funded by the sugar industry paid US$20,000 towards the consultation.
ILSI - the International Life Sciences Institute - an American research group paid for by food companies like Coca Cola and Tate and Lyle also put in US$40,000.
Panorama reveals that ILSI was also invited to suggest who might sit on the consultation and even nominated the chairman months before the experts ever came to Rome.
This funding deal was agreed with the FAO's then Director of Food and Nutrition, John Lupien.
This news came as a surprise to the committee members that Panorama spoke to, none of whom had any idea that the research had been funded by the sugar industry.
Professor Mann, said: "My guess would be that I certainly and probably my colleagues would not have been prepared to be involved with such an activity had it been funded by these organisations.
"I believe that it would be impossible to produce an unbiased report when the source of funding came from groups with clearly vested interests."
But another shocking fact was to come out of the committee discussion.
The experts Panorama spoke to claim they had agreed on a limit of between 55 and 75% on how much carbohydrate we should eat. But when the report came out the upper limit had gone.
Professor Mann complained that a report which failed to mention a limit on carbohydrate - or on sugar - was open to abuse.
He added: "I think it would clearly be to the advantage of the industry not to have an upper limit, because increasingly the industry are producing food products which are reduced in fat, and one way of compensating for fat is to increase the amount of sugar.
"So obviously if there's no upper limit of sugar, one can add sugar with impunity into a whole range of food products."
The FAO's Assistant Director General, Hartwig de Haen, was also surprised at Panorama's revelations.
"If the funding was accepted together with influence of the choice of experts or of the wording of the report then it is unacceptable, that is true," he said.
A statement from the FAO confirmed that the ISLI and the WSRO were asked to propose names of experts for the consultation but that the FAO had the final say.
It went on to say that the lack of rigid guidelines meant the consultation was not illegal but "did contravene common sense norms of transparency and the avoidance of perceived conflict of interest."
The FAO said the sugar lobby had misquoted and misinterpreted the recommendations of the 1998 study.
It added that the WHO has been working on reconvening a Carbohydrates consultation, and that this matter was now "regarded as urgent".
ILSI also said it only suggested names of experts to be on the committee, adding: "We did not suggest a specific person as the Chair; it is our understanding that decision is made by the experts themselves.
"We see no reason why ILSI's partial support of the consultation or our participation in the process would call into question the credibility of the consultation."
John Lupien, contradicted Mr de Haen and said that it was normal practice to seek outside funding for studies, adding: "The sources of these funds were not made known to the experts, and were not acknowledged in the final report since this was routine FAO/WHO practice."
He added that the experts had approved the draft agenda and elected Professor David Lineback as their Chairman.
Panorama: The Trouble With Sugar was broadcast on BBC One on Sunday, 10 October at 22:15 BST