COOKEVILLE, Tenn. -- The TBI investigation into allegations against District Attorney Bill Gibson has raised some serious legal implications.

It all involves a post conviction relief petition filed by convicted murderer Chris Adams against his trial attorney.

Adams was convicted in November of 2004 in Cookeville of second degree murder, especially aggravated robbery and two cases of theft of property.

He is serving sentences totaling 35-years at the Southeast Region State Correction Facility in Pikeville.

In his post conviction relief petition, Adams accused his lawyer, Public Defender David Brady of being an ineffective counsel while representing him at the trial.

Adams asks that his guilty plea be set aside and that he be given a new trial.

But, Channel 4 News is told that it was the prosecutor who may have allegedly suggested grounds for the convicted murderer to get a new trial.

That was done, a source said, through 13 letters reportedly sent by the District Attorney to Adams, who was in prison at the time. This was done without the knowledge of Brady, Adams' attorney.

Attorney Phil Parsons of Cookeville was Adams' lawyer on his post conviction petition, but no longer represents the convicted murder.

The letters between Gibson and Adams reportedly came to light when Parsons went to the prison to interview his client and uncovered the letters he says the district attorney sent him.

They reportedly indicate a close relationship between the D.A. and Adams.

The Cumberland Courier newspaper in Cookeville, in Friday's edition, quotes one of the letters from Gibson to the prisoner, as saying the following:

"I am taking a chance by writing to you without your attorney knowing it. It would mean a lot of trouble for me if you ever mentioned it."

The newspaper story said that Gibson said in the letter that he would offer a favorable plea agreement and said: "Keep everything I have said here and even the fact that I have written to you under your hat."

The district attorney was said to have concluded the letter by allegedly writing: "Let [Public Defender] David Brady tell you the news and act surprised."

Some of the 13 letters were typed and some handwritten and one of the letters was signed "Bill Gibson."

A local attorney says it’s a no-no for a prosecutor to meet or talk with a defendant without the presence of his lawyer.

TBI agents, I have learned, have already interviewed both Gibson and Brady, during the past several weeks. The investigation is continuing while others are interviewed.

Gibson released a statement Thursday that said, "I believe some allegations have been made by a local attorney having to do with whether or not I communicated with a defendant without the permission of his attorney."

The question being asked around the Putnam County Courthouse is what was Gibson's purpose in getting involved with a convicted defendant's petition in order to get his trial overturned.

Brady has been the Public Defender for 17 years, and during the first eight years, he and Gibson were at war with each other.

It's believed there has been no trouble between the two officials since then.