A report by British MPs has found that PricewaterhouseCoopers (PwC) promoted and facilitated "industrial scale" tax-avoidance.

The accounting firm is said to have written more than 500 letters to authorities in Luxembourg, on behalf of more than 300 international clients.

One highlighted PwC scheme saw a Shire Pharmaceuticals’ subsidiary in Dublin lending billions to another subsidiary based in Luxembourg - the report found that it only paid 0.0156 percent tax to local authorities.

The company is incorporated in Jersey, but moved its domicile to Dublin in 2008. Most of its 5,600 employees are based in the United States - it employs 300 people in the UK - 100 in Ireland - and two in Luxembourg.

These two workers are responsible for managing loans worth £10bn (€13.4bn) - the committee said that: "Neither PwC nor Shire could demonstrate that the company’s presence in Luxembourg was designed to do anything other than [to] avoid tax."

The MPs also accused PwC of misleading the committee at an earlier hearing:

"We consider that the evidence that PwC provided to us in January 2013 was misleading, in particular its assertions that 'we are not in the business of selling schemes', and 'we do not mass-market tax products, we do not produce tax products, we do not promote tax products'," said Margaret Hodge, chairwoman of the House of Commons’ Public Accounts Committee (PAC).

PwC said that it disagreed with the report, saying: "We stand by the evidence we gave to PAC."

The company did acknowledge that the tax systems had been too complicated:

"We agree the tax system is too complex, as governments compete for investment and tax revenues."

Adding: "We take our responsibility to build trust in the tax system seriously and will continue to support reform."