Sky Sport Italia ran the story this evening with transfer expert Gianluca Di Marzio making the claim.
Spurs have long shown an interest in Guarin and Alvaro Pereira, both specific targets for manager Andre Villas-Boas.
According to this report, Tottenham raised their proposal to €20m – around £17m – but the Nerazzurri rejected it.
However, the same sources suggest Inter hope to spark a bidding war and are prepared to listen to higher offers.
Colombian international Guarin turns 27 on June 30 and only joined Inter from Porto in January 2012.
He arrived on loan for €1.5m (£1.2m) and in May 2012 the club took up its option to make the move permanent for a further €11m (£9.3m).
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