Ex-NY Giants CB DeAndre Baker is officially off the hook in his armed robbery case -- after some alleged funny business with the witnesses who initially said they saw him commit a crime at a cookout back in May.

As we previously reported, Baker -- along with Seattle Seahawks cornerback Quinton Dunbar -- was arrested for allegedly robbing several people at gunpoint during a cookout in Miramar, FL.

Baker was initially charged with 4 counts of robbery with a firearm over the May 13 incident and was facing up to life in prison.

But Monday morning, prosecutors announced all charges against Baker have been dropped because of serious issues with the alleged victims and witnesses.

Prosecutors say three alleged victims had initially filed sworn statements "in which they asserted that three men committed a robbery with a firearm upon them and that Mr. Baker was one of the assailants."

Then, something changed ...

Prosecutors say, "the alleged victims and the known witnesses have become uncooperative and their credibility is inalterably tarnished."

In fact, prosecutors say they tried to have one witness held in contempt of court for refusing to answer questions.

And get this, prosecutors also say an attorney representing three of the alleged victims was arrested Monday morning for extortion "related to soliciting a cash payout on behalf of the three men in exchange for altered testimony."

In other words, officials believe the lawyer was helping his clients get money in exchange for changing their stories.

Prosecutors say the alleged victims ultimately recanted their initial claims -- that Baker was involved in the crime -- and most recently said that he was "present" at the cookout but did not rob or assault anyone.

Because of all the alleged shenanigans involving the victims and witnesses ... prosecutors have just decided to drop the case against Baker altogether -- seemingly because they realized they would not be able to prove his guilt beyond a reasonable doubt.

Baker -- who was drafted by NY in the 1st round of the 2019 NFL Draft -- was cut by the Giants back in September over his alleged role in the incident.

At the time, cops said witnesses told them Baker pulled out a semi-automatic firearm after a dispute at the cookout and directed Dunbar to start taking watches, cash and other valuables from partygoers.

Baker had denied the allegations through his attorney.

The 23-year-old has remained an NFL free agent while his case played out in the courts. It's unclear if he'll still face league discipline even with the charges being dropped Monday.