Kenny Rogers Estate Sues Longtime Friend Over Farewell Tour DVD

One of Kenny Rogers' longtime friends did NOT know when to fold 'em, because he allegedly produced an unauthorized DVD of Kenny's farewell tour ... and now his estate is suing.

The estate claims Kelly Junkermann, an employee and friend, went rogue after he recorded Kenny's last tour and tried to release a DVD called "Kenny Rogers -- The Gambler's Last Deal."

According to legal docs, obtained by TMZ, the estate claims Junkermann convinced the singer to let him shoot the farewell tour -- but Kenny made it crystal clear the footage would be for Kenny's personal use only ... and NOT for commercial release.

The estate claims Junkermann ignored that condition and went ahead and made a DVD filled with "priceless and irreplaceable audio, video, photographic and audiovisual content that were compiled over the course of Kenny Rogers' decades-long career."

What's more ... the estate claims Junkermann made repeated requests for approval to use the content, but was repeatedly denied verbally and in writing. The estate is adamant Junkermann knew he had no right to go forward, but still struck a deal with a distributor.

Earlier this year, the estate says it blocked the release of the DVD but it cost nearly $290k in legal fees to get it done. So, they're suing for damages and for an injunction blocking Junkermann's DVD from ever coming out. They say it's not up to Kenny's standards and would damage his brand.