West Ham are confident that the deal to move into the Olympic Stadium does not contravene domestic or European legislation.

The Premier League club are set to move into the London 2012 showpiece venue for the start of 2016-17 season, but the journey there has been a tortuous one, fraught with controversy.

Fresh questions were raised about the award of the 99-year lease to West Ham on Tuesday, when it was suggested the deal may contravene European state aid law.

The report suggests the failure of London Mayor Boris Johnson and the London Legacy Development Corporation to obtain prior approval from the European Commission before signing the deal opens up the possibility of challenges from anyone who feels disadvantaged.

That could leave West Ham facing a large compensation bill, but the club defended their position in a lengthy statement about the Olympic Stadium deal. A West Ham spokesman said: "West Ham United is confident that its agreement with the LLDC complies with all relevant UK and European legislation and categorically does not constitute state aid. "Indeed, the European Commission looked into a complaint in relation to our move to Queen Elizabeth Olympic Park in 2013 but 'decided not to further pursue' the matter.

"The club was selected as anchor concessionaire following a fair, transparent and robust process that was open to any group or organisation in the country. "Out of the four proposals submitted, West Ham's was selected as it delivered a sustainable and viable future for the Stadium and, crucially, provided the best return for the taxpayer.

"The agreement with the LLDC will see West Ham make a substantial capital contribution towards the conversion works of a Stadium that it may only rent for up to 25 matchdays a year, pay a multimillion pound annual usage fee, as well as offering a share of food and catering sales from its supporters.

"The worldwide draw of hosting the most popular and watched football league in the world in such an iconic venue will add value to any sponsorship and commercial agreements related to the Stadium, which the public purse stands to further benefit from.

"It is clear that the linking of the naming rights to West Ham United generates real cash value for the LLDC. "Without West Ham United, the Stadium would continue to cost the taxpayer millions of pounds a year.

"With us, the public purse will see a return on the hundreds of millions of pounds that were committed to build the Stadium, long before West Ham's association had begun."