It is meant to breathe life into money-spinning ideas and put fire into the belly of would-be entrepreneurs. But fledgling tycoons seen shaking hands with millionaires on BBC2’s reality TV show Dragons’ Den have revealed that much of the cash shown on screen is never handed over.

Once the television cameras stop rolling, checks have to be done, agreements have to be signed and a working relationship established. It is then that the two sides can fall out.

The contestants claim that the dragons, who have their own businesses to run, sometimes devote too little time to the projects they have offered to back and treat entrepreneurs as little more than employees.

The dragons return the fire, saying contestants can exaggerate to win investment funds, act as though they have won a cash prize in a quiz or talent show and refuse to sign carefully drawn legal documents.

Dragons’ Den, now in its sixth series, is hosted by Evan Davis, co-presenter of Radio 4’s Today programme, and has about 3.5m viewers an episode. Eccentrics and aspiring tycoons pitch their money-making ideas to the panel of entrepreneurs, the dragons, and ask them for money. After interrogation they are either dismissed or given an offer of thousands of pounds of backing.

Not all ventures turn out well. Casey Jones, a former fire-fighter turned inventor from the West Midlands, was seen on the show last year waving a smelly shoe under the noses of Duncan Bannatyne and the other dragons as he demonstrated his Klenz deodoriser, a microwave-like device that kills germs and odours on anything placed inside it.

He won an offer of £100,000 in investment from two of the dragons, Deborah Meaden and Richard Farleigh, in return for 50% of the business.

Within a few months the deal had fallen through. “Deborah was a real dragon. We did not exactly fall out but she was very pedantic and was demanding that I work on that one project exclusively. I would effectively have been her employee,” he said.

“Casey Jones presented one product, the foot deodoriser, and we agreed to invest with a condition that there was a patent on the product. He wanted us to invest in a range of 25 to 30 products, none of which I knew anything about,” Meaden said.

“That would not have stopped the relationship if it had been a good relationship but he said the foot deodoriser had a patent and it didn’t. We didn’t find that out until two months down the line and there were fears of copycat machines on the market. I am amazed he says I was a dragon. I thought we got on well. As for being pedantic, if he means keeping him to his word, yes, I am a stickler for detail.

“There are success stories. We have launched a new mix album system and a unique system to mix music for exercising to. It would never have happened if I had not got involved. I put in £160,000 for a 40% stake.”

Shane Lake, an Australian, sought a £100,000 investment in Hungry House, which allows customers to read reviews before ordering from a variety of restaurants.

Bannatyne and James Caan each offered £50,000 for a 25% stake, which was tentatively agreed. But it, too, fell through after four months of meetings.

“You go into the Den on the understanding they do a deal on the gut reaction they have on the day,” Lake said. “You don’t expect massive due diligence and 20 pages of heads of terms before you even get to a shareholders’ agreement.”

Caan said: “The impression may be that you come off the show and the dragon writes you a cheque for £100,000, but that would not be good business practice. In the case of Hungry House . . . the financial model just did not work.”

Some budding entrepreneurs claim better deals can be done away from the show. Lara Goodbody, co-founder of YogaBugs, which runs yoga classes for children, declined £200,000 for 30% of her business, opting instead for £250,000 for a 15% stake from a private investor.

“Dragons’ Den is great fun but it’s not the best way to find an investor,” she said.

Bannatyne said: “Over the first five series about 70% of what we did worked out.”

The BBC said: “All investment pledges are made in good faith. These are real businesses and real negotiations and some deals can fall through for a variety of reasons.”

Additional reporting: Helen Brooks, Nicholas Mills

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