Margaret Hodge, who chairs PAC, said: "Promoters of 'boutique' tax avoidance schemes like the one brought to our attention by the case of Jimmy Carr, are running rings around HMRC.
She added that schemes which exploit loopholes within the system are being taken advantage of.
"It has allowed a system to evolve where the dice are loaded in favour of the promoters of tax avoidance schemes," she said.
More top news
A vote to remain in the EU will see Brussels exert more power over the NHS, according to the Cabinet minister.
Tuesday: A cloudy, cool and dull day with outbreaks of heavy rain becoming lighter and patchier.
The former England cricketer fears England will become "cluttered" unless it leaves the EU.