4/8 8 AM PT -- Jones is further clearing the air regarding his interaction with the drug tester ... saying he was NOT arrested over the incident.

"I must admit, it's disappointing to have to clarify these things again, but I understand that I may be an easy target given some of my past issues," Jones said. "It's important to set the record straight and make sure the truth is told."

Jones reiterated he was upset when the tester showed up to his home ... and he was "caught off guard" as he was taking a nap at the time. Jones admitted to using profanity after growing frustrated with the administrator's "unprofessionalism and protocol," but other than that ... he claims he did nothing wrong.

"It's unfortunate that false news has been spread without proper fact-checking," he added. "I want to assure you that I will vigorously defend myself against these baseless accusations. The truth is, the incident simply did not occur."

UFC champion Jon Jones is adamantly denying any wrongdoing after a drug tester showed up at his place unannounced ... saying the whole interaction was as cordial as could be.

Jones -- a 36-year-old fighter -- claims he was at his home in Albuquerque, New Mexico last weekend ... when out of nowhere, a UFC-certified official showed up to test his blood while he was celebrating a birthday.

In a police report filed by the alleged tester, Jones is accused of grabbing the official's phone and threatening to kill her ... but he says there's video to prove there was no bad blood.

Here's Jones' statement in its entirety.

"I want to address reports about me allegedly threatening a drug tester's life and taking a phone," Jones told TMZ Sports. "I want to clarify that there is a video showing both drug testers leaving my home after the testing session, where we exchanged a high five and a hug. Although I was frustrated with the unprofessionalism and used profanity out of frustration it ended friendly and amicably, nothing threatening at all."

"I was actually celebrating a friend's birthday party at my home, and I believe it's perfectly normal to celebrate in the comfort of my own home."

He continued ... "I must say, this particular tester behaved quite unprofessionally and even breached standard protocol along with HIPAA laws. Throughout my 20 years of being subjected to drug tests, I have never encountered such an incident with a DCO officer before."