Pietersen, sacked by England in February 2014, was told by Graves in March that if he scored runs in county cricket he would be considered for selection again.
But, having made a career-best 355 not out for Surrey, the controversial batsman was told by newly appointed England cricket director Andrew Strauss on Monday that he would not be recalled this summer.
"I didn't make any promises," Graves said, in an ECB statement, on Friday.
"There were no guarantees that if he (Pietersen) chose to exit his IPL (Indian Premier League) contract, play county cricket and score runs he would be selected for England. And I said he should make any decision on his future on that basis."
Pietersen reacted angrily to Strauss's decision, describing the ECB's behaviour as "deceitful" earlier this week.
"In the past few days my integrity has been called into question, something I can't accept," Graves said.
"Throughout my business career and my years at Yorkshire, integrity has been my watchword. It governs everything I do and is an important part of what I bring to the ECB.
"So it saddens me that what was a private conversation with Kevin in March has been used to do just that."
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Image: Surrey's Kevin Pietersen during the team's photo session.
Photograph: Philip Brown Livepic/Action Images via Reuters