Desperate to help their troubled daughter, Britney’s divorced parents Lynne and Jamie Spears have hired a private eye to track her, insiders say.

But her parents were not around when top detox specialist Dr. Stuart Finkelstein rushed to Britney Spears’s Beverly Hills mansion during her recent crisis, sources say.

“Britney was in a really bad way – even for her,�? a close friend of the singer told The ENQUIRER.

“She was extremely depressed, seemingly disoriented and out of control. She’d just finalized some tour date, and she realized that she had to get herself together if she was going to go out on the road and perform.�?

So Britney contacted Dr. Finkelstein – called Dr. Stuey by some of his patients, who has also treated Michael Jackson and Robert Downey Jr.

“Dr. Stuey has treated Britney before, so she felt comfortable calling him again,�? said her friend.

“Even though it was Sunday, she begged him to drive to Beverly Hills. Obviously, Dr. Stuey felt Britney’s condition was serious enough for him to drop what he was doing and rush up to see her.�?

Besides the pressure of touring to promote her comeback CD, Britney faces a legal battle with Kevin Federline over custody of their two boys.

“Britney feels that Kevin could file a motion for full custody any day now – and her lawyers have advised her that she needs to be 100% drug-free to keep the current custody agreement in place,�? said the source.

“She’s also hired another agent to help her score a spot on the upcoming Video Music Awards – and that’s not an appearance to take lightly,�? said her friend.

And if she’s serious about staying clean, she’s on the right track with Dr. Finkelstein, an internal medicine physician who developed a ground-breaking technique called “blood cleansing.�?

He uses a pharmacological innovation called Suboxone, which allows patients to detox on an outpatient basis. Approved by the FDA in 2002, Suboxone is one of the first addiction-fighting drugs that can be prescribed and administered from a doctor’s office.

Although Britney has denied having a drug or alcohol problem, she spent a month at Promises rehab in Malibu earlier this year.

And in a worldwide exclusive, an insider tells The ENQUIRER that she’s used drug-laced “lollipops�? for the past three years.

“Britney carries the ‘pops’ in her purse,�? revealed a source.

“It’s an inside joke that when Britney says: ‘I’m craving candy right now. I need a lollipop,’ what she’s really saying is: ‘I need to get high.’�?

Britney was introduced to the “drug lollipops: while on her “ONYX�? tour in Europe in 2004, said her friend. In Amsterdam, she visited legal marijuana cafes where the lollipops were sold.

After the tour, Britney found a place to buy marijuana “pops�? in Santa Monica, said the source. But the insider claims she soon graduated from marijuana-laced lollipops to pops laced with a morphine-like drug that’s an even more potent narcotic.

“The morphine-laced pops are round and look like gumballs,�? said the source. “Britney was photographed with them in New York right before her breakdown. Sometimes she’d pass out after sucking a morphine pop. She mixed it with alcohol and could barely stand up and ended up throwing up.

“Now it is as if she uses the pops as a substitute for pain pills or Vicodin.�?

While the insider says Britney treats the lollipops like candy, they’re potentially lethal.

Approved by the FDA in 1998 to treat severe pain in cancer patients, they contain the powerful narcotic painkiller fentanyl citrate. It’s highly addictive and 80 times more potent than morphine. The narcotic lollipop has been linked to 127 deaths. Of those, 47 have been associated with addiction, overdose, or misuse.

Britney’s mother Lynne first heard of her daughter’s use of the drug-laced lollipops when Britney detailed her drug history before being admitted to rehab, according to an insider.

“Until then, Lynne never even knew drug lollipops existed,�? said the source.

Spurred by the discovery, Lynne has joined forces with her ex-husband Jamie – hiring a private detective to keep an eye on Britney, says the source.

“Britney’s mom and dad are very concerned about her,�? another source close to the Brit tells The ENQUIRER.

“Although Lynne and Jamie are divorced, they’re united about seeing to Britney’s well-being. So they’ve hired a private eye to watch her. The detective keeps track of Britney’s affairs, especially her personal life, and reports back to Lynne and Jamie. Since Britney cut off almost all communication with them, they felt they had no other choice.�?