You should eradicate any contact with this person especially while on Parole. I would ask your attorney to contact your parole officer to illustrate that no foul play has been done on your part. With respect to the eaves dropping issue. It is unlikely, but I don't know what charges your faced.
Please contact a lawyer and do not make legal decision based on the legal advice provided. Criminal cases are complex and factually very sensitive.
First and foremost if a no contact order is in place, do not have any, direct or indirect contact with the person(s) covered by the order.
Direct means contact that is between you and him/her in person, via telephone, by mail, etc.
Indirect means contact thru another person.
Consult an experienced criminal defense lawyer to advise you regarding the attempts by the covered person to contact you.
It is possible but not probable that your mail and telephone are being monitored "parole".
Of course, every answer is based on the question asked and requires a more complete context. This answer should not be relied upon to make a legal decision. Seek the advice of an experienced criminal defense attorney before acting. Law Offices of Raymond G. Wigell, Ltd. Defenders of the Constitution since 1975/ Aggressive Creative Defense Strategies/ Website: www.waaltd.com 24/7 --(708) 481-4800.
No contact means NO CONTACT - either personally, through letters, email, text, Face Book, etc. It is highly unlikely that someone from the prison told your co-defendant that it is OK to write to you. However, even if that did occur, this is a violation of the order. Either return the letters, or bring them to your parole officer - unopened. Speak to your lawyer if you have further questions. Do not violate the no contact order!