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
Scotland's top prosecutor and an FBI director met to discuss the progress of further investigations into the Lockerbie bombing.
A Ukip councillor has been expelled from the party after allegedly making "jaw-dropping" comments in a TV interview.
"He was their for me everyday of my life, he was the best father I could ask for," Rafael Ramos's 13-year-old son said.