You pay us £300. However, your invoice will say £600. So £300 stays with you. Within minutes of the conversations beginning, it became apparent that the executives were prepared to enter into highly questionable arrangements which legal experts said last night should be investigated. An executive from Pharmarama, a company based in Hertfordshire, was happy to describe how pharmacies could exploit the NHS system for funding specials with so-called "rebates" or discounts. "Explain the rebate again?" asked a reporter, in the middle of the crowds of delegates. "Rebate is where we will charge you a certain amount," said Dhruv Patel, the head of unlicensed pharmaceutical sales at Pharmarama. "Ok, let's say £600," said the reporter. You pay us £300, however, your invoice will say £600," said Mr Patel. The £600 billed by Pharmarama would be refunded to the chemist in full by the NHS - with the drugs firm and the chemist effectively splitting the proceeds. Mr Patel then explained how the company would provide credit notes and pointed out that the NHS only had the capacity to look at invoices rather than conduct any forensic analysis of a company's income. Mr Patel gave an example of how discussion of the payment would proceed between the chemist and NHS officials. Can you show me an invoice to show that you've actually paid £600. Of course I can. There you go. "Er, that's it," explained Mr Patel. He also boasted that the company knew where the "thresholds" were for different local NHS bodies without raising alarm bells. Several pharmaceutical companies have the ability to supply the huge range of "specials" now being marketed, with chemists able to supply - and charge taxpayers - for more than 20,000 different products. Quantum Pharmaceutical, which describes itself as the leading supplier of "specials" and was at the conference, offered a slightly different arrangement when undercover reporters met one of its managers in Newcastle. Leo McDermott, its business development general manager, said: "We'll charge you 150 per cent [of the cost of the drug]. Your 50 per cent stays in the Royal Bank of Quantum until you see fit to claim it back. Mr McDermott also suggested that his company could supply generic drugs free of charge in return for the right to supply the chain of pharmacies with special drugs. Reporting a conversation he said had taken place with a high street chemist, he said: "I said 'you've got an account with [generic drug manufacturer], why don't I just buy two and a half grand's worth of generics from them, we'll get it delivered into Quantum and then delivered [to you]." So we're not, no one's breaking the law. We're not laundering money or anything," said Mr McDermott. Alternatively, he suggested simply invoicing Quantum at regular intervals, with around £10,000 a month being paid to the pharmacy chain for its business. Or you can write us an invoice for £10,000 ... simple as that. And between two large companies that's completely legal. Quantum have had the best lawyers in the world on this. It's completely legal. And little Mr Patel on the high street [thought to be a reference to chemists] they like to duck and dive and get the money back in different ways but a large company like you guys, you, you invoice me once a quarter for £40,000. Dead easy, dead easy," he said. Zaheer Mushtaq, an executive from another drug company, Temag, which was represented at the conference, said in a meeting at his firm's offices that his company would provide "almost like a duplicate invoice if you like - a double invoice, one with before discount and then after the discount so they can see the amount of discount that they're getting." Mr Mushtaq said that after the company supplied the two invoices it would be up to the pharmacy which one they claimed back from the NHS. You could call that slightly perhaps underhand, but you know if that's generally what they want, all we're doing is we're just endorsing the price. And the discount will go back to the pharmacies, and it's up to them ... Another way of maximising payments from the NHS is a practice known as the "wholesale" system, which one executive described as the "magic triangle." Under this system, the pharmaceutical company sells the drug to a wholesaler, who then sells it on to the pharmacy at an inflated price. The pharmacy then invoices the NHS. Some representatives suggested that the undercover reporters may also want to set up a wholesaler - at arm's length. "If you have friends who you see who have a wholesaler dealer's licence - and I do - then that might work to your advantage of how you would like to structure a deal," said Mr McDermott, of Quantum. First of all we need the relationship. We need to understand that. The problem is every time you bring a third party in, everybody needs to win. If you know what I mean. Mr McDermott explained that the wholesaler and the pharmacy needed to "appear to be different." Well, one might be owned by his wife. One might be owned by ... Tonight the companies named denied wrongdoing and two of them launched investigations. Magdalena Kulbat, of Temag, said: "It would be totally unrepresentative to make any suggestion that we are involved in any sort of practice to unfairly charge the NHS ... we are not involved in anything that seeks to be fictitious to make money from supplies to chemists." She said that it was "totally inaccurate" to suggest that the company supplies "duplicate invoices with different amounts." A spokesman for PIL [Pharmarama International Limited], said they were investigating the allegations made by The Telegraph. Our initial inquiries suggest strongly that the issue at stake relates to inappropriate and overenthusiastic claims made at a sales meeting. The spokesman said their company "has never conspired with pharmacists" and they do "not offer a rebate scheme." However, they admitted that on a "small number of occasions, we have complied with a customer request to invoice at the full price and offer a negotiated discount by way of a credit note," but when this happened, they reminded the pharmacists of their "obligation under the NHS Act to keep the NHS properly informed." A spokesman for Quantum Pharmaceutical said they were investigating the allegations and had suspended a member of staff. "The alleged views of this individual do not represent the business practice of this company," said the spokesman. Wholesalers are prevalent throughout the sector, but it is not our position or policy to advise whether customers should or should not operate a wholesale licence ... the alleged views of this individual do not represent our business practices. They said that they did not give "monies in return for customer trading" and offered "lawful, competitive and transparent discounts." The spokesman said they were "legally entitled to offer discounts" and it was common business practice.