Nigel Farage has suggested pharmaceutical companies lobbying the EU have put people producing alternative medicine "out of business".
Mr Farage was asked whether it was worth risking the pharmaceutical industry losing billions of pounds and thousands of jobs if Britain left the EU.
He replied: "I don't buy the fact that a pharmaceutical company is in Britain because it's in the EU.
"I'm not wholly happy with the way that much of the pharmaceutical industry has behaved.
"In particular I see their lobbying in Brussels, which is absolutely massive, and I see the way they've been very good at putting out of business people producing alternative medicine."
He added: "Only 12 per cent of the entire British economy is exports to the EU.
"Our biggest industry isn't pharmaceuticals. It's financial services of all kinds."
The audience member who asked the question then tells Mr Farage: "But alternative medicine has not actually been proven against placebo."
A recent systematic review of research around homeopathy found it to be no more effective than placebo.
During the debate Mr Farage also told an audience member to "calm down" when she asked him to explain his suggestion that women could be at risk of sex attacks from refugees if Britons vote to stay in the EU.
The Ukip leader was criticised by a fellow Brexit campaigner earlier this week for "outrageous blatant scaremongering" over his suggestion women could be at risk of sex attacks from refugees if Britain stays in the EU.
Mr Farage had said the possibility of such attacks in the UK will be "the nuclear bomb" of the referendum campaign.
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