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.”