The bombshell allegations surfaced Friday in Hulu's "Controlling Britney Spears" ... which details accounts from people who say they were involved in the inner workings of Britney's conservatorship, as well as what allegedly went into monitoring her.

According to a guy named Alex Vlasov, he worked for a security company called Black Box ... which he says Jamie and a woman named Robin Greenhill -- who worked for Tri Star, Britney's business management company -- hired to keep tabs on Britney for years.

He claims Black Box had him set up an encryption system on Britney's mobile devices ... so texts and emails she'd send and receive would loop back to Jamie and Robin via a separate iPad they had. He likened it to parents keeping a watchful eye over their minor children's activity.

Then, Vlasov went on to claim that Jamie was controlling and overbearing over people who could interact with Britney ... especially men.

Vlasov alleges Jamie set up some sort of listening device in her bedroom ... alleged audio of which Vlasov says he was once asked to destroy.

He felt super uneasy about the demand and made a copy ... but he doesn't reveal any of the contents of what's on those recordings, which he says amounted to about 180 hours worth, ranging from convos she had with Sam, her kids and others.

The timing of the doc couldn't have come at a better time for Britney -- because she's going to try and get her father off the conservatorship once and for all next week ... and possibly attempt to end the whole thing altogether. We broke it down in this week's podcast.