Sir Brian Jarman, Emeritus Professor at Imperial College's School of Public Health has said information on higher-than-expected death rates was ignored for more than a decade.
He told BBC Breakfast: "My view is that there was political pressure for the information to be ignored and had been ignored at least since 2001.
"I actually sent the data to Andy Burnham in March 2010 and seven of the hospitals in the 14 were among the ones that I sent him."
"We published the information in national newspapers every year from 2001 onwards," he added.
Mr Burnham was in charge of the NHS between June 2009 and May 2010.
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