from www.tmz.com – Ryan Jenkins wasn’t the only man in Jasmine Fiore’s life … so was convicted felon Michael Cardosi.

Newly discovered love letters she exchanged with him in prison could shed light on her murder.

We’ve learned Fiore met Cardosi at the gates of a southern California prison when he was released on parole Aug. 11th — just four days before her mutilated body was discovered.

Then, on Saturday the 15th, Cardosi was re-arrested for parole violation — which lead to a search of his apartment.

Buena Park police tell us that search uncovered letters the two had exchanged … revealing an intimate relationship during — and possibly before — his imprisonment. The letters are being held as evidence in the case.

We’re also told by police — and friends of Cardosi and Fiore — that the two were also previously married … though no certificate has surfaced.

Cardosi has been eliminated as a suspect in Fiore’s murder.