UKIP's leader in Wales says the British welfare state is subsidising workers from across the world.
Nathan Gill has called for greater controls over the quality and quantity of migrant workers.
He told BBC Wales Today on Monday that migrants were taking money out of the economy.
He said: "The vast majority of migrants send a great deal of their pay packets back home which is taking money out of our local economy.
"It does not necessarily just mean it's a booming economy for everyone.
"A lot of people work the minimum amount of hours they need to in order to claim working tax credits. We are subsidising workers from all over the world. The system is wrong."
He also accused scientists of changing their minds more than politicians after being criticised by opposition parties for claiming that mankind was not responsible for climate change.
He made his views known on climate change when he outlined his opposition to wind farms during an interview on Radio Wales on Sunday.
Today he said: "Scientists flip-flop more than any politician ever has.
"All I'm saying to people is don't take anybody's word for it, use your own common sense.
"We have got this wonderful resource of the internet, go out there, do your own research and think for yourself.
"I know for a fact that covering Wales in wind farms will not stop global warming."
The interview with Mr Gill was the fifth in a series of Wales Today interviews with Welsh political leaders.