New bombshell allegations that  may cost Jon Gosselin his legal war with TLC AND custody of his beloved children as well!

Jon Gosselin‘s day in court could end with him losing his children – due to a sex tape scandal and allegations of cocaine use!

Jon’s bodyguard Thomas Meinelt has been subpoenaed to testify in TLC’s lawsuit against Jon, and The ENQUIRER has learned Meinelt claims he saw Jon snort cocaine many times, and that he’s watched Jon’s secret sex tape!

"Tom told me that Jon was secretly videotaped having sex with a woman in Los Angeles in October, and he’s seen the tape!" said Stephanie Santoro, Jon’s former flame and family nanny.

"Tom said people close to Jon put a camera in his hotel room, and paid a girl to flirt with Jon and have sex with him.

"He also told me that he saw Jon snort cocaine on more than one occasion, and that the more Jon got into partying, the more cocaine he used!"

As The ENQUIRER previously reported,  sources say Jon’s on-off GF Hailey Glassman sold and used cocaine while in college.  

PLUS! SEE the legal docs on Jon’s countersuit against TLC and his request for a preliminary injunction.

For the FULL STORY with all the details you won’t find anywhere else pick up the new ENQUIRER now on sale!