Mariah Carey used her assistant's credit cards pay for and conceal plastic surgeries and spending sprees, sources familiar with the singer's inner workings tell DailyMail.com.

'Mariah never wanted people to know about her shopping or surgeries so she would put them on [former assistant] Lianna's [Shakhnazaryan] card or [former manager] Stella's [Bulochnikov] cards,' an insider said.

'She has an AMEX card of her own but her business management team only let her have one because of her spending - she always spent so much on it, it would get maxed out.'

'All the staff, including her security guards and nannies, have to put stuff on their cards and get it reimbursed.

'Even for things like the children's McDonald's. They were never given money up front or petty cash.'

Mariah Carey used her assistant's credit cards pay for and conceal plastic surgeries and spending sprees, sources familiar with the singer's inner workings tell DailyMail.com

Carey's former assistant Lianna Shakhnazaryan (pictured together in May 2017) accuses the singer of spending money on credit cards registered to Shakhnazaryan – including on surgical treatments such as buttocks enhancement

The diva, 49, is currently embroiled in a court battle with her former friend and employee over claims that Lianna Shakhnazaryan, 36, spent money on Carey's personal credit card and secretly filmed her.

Shakhnazaryan filed a counter-suit in January alleging she endured battery and racial abuse from the singer, who is currently on tour in Europe.

And now court documents exclusively obtained by DailyMail.com allege that Carey would spend money on credit cards registered to her assistant and the expenditures were supposed to be reimbursed by Carey.

Shakhnazaryan also claims in court documents that she was asked by Carey to make some of the purchases on her behalf and was promised reimbursement.

Repeated attempted to get comment from Mariah's representatives by DailyMail.com have been unsuccessful.

While Carey has previously denied having surgery, invoices indicate at least six cosmetic procedures – including fat freezing and firming treatments.

A source told DailyMail.com that Shakhnazaryan was routinely ordered to purchase items on Carey's behalf and would either have the money reimbursed or use a company card given to her by Mariah's management company, Boulevard Management.

One invoice seen by DailyMail.com was for a total of $32,765, and included a $10,000 in PLLA buttock filler injections, a $4,800 LipoFreeze fat-melting laser treatment to her upper breasts and an $8,900 firming ultrasound procedure to her neck and jawline.

The receipt, issued by the upmarket Epione Beverly Hills clinic, is billed 'Stella Carey' - believed to be a pseudonym used by Carey -but was sent to the singer's Manhattan mailing address.

While Carey has previously denied having surgery but invoices show at least six cosmetic procedures – including $10,000 in PLLA buttock filler injections

One invoice seen by DailyMail.com from April 2017 was for a total of $32,765, and included a $4,800 LipoFreeze fat-melting laser treatment to her upper breasts and an $8,900 firming ultrasound procedure to her neck and jawline

A separate bill, paid for using Shakhnazaryan's own American Express credit card, totaled $7,915 and was for a vShape tightening radio-frequency treatment to the thighs, ostensibly for the singer, plus a $485 case of protein shakes

Pictured: Carey on April 30, 2017, a few days after Shakhnazaryan's AMEX was charged for neck and jawline firming treatments

A separate bill, paid for using Shakhnazaryan's own American Express credit card, totaled $7,915 and was for a vShape tightening radio-frequency treatment to the thighs, apparently for the singer, plus a $485 case of protein shakes.

On the receipt, Carey was registered under 'Margot Channing' – another pseudonym the star often uses to check into hotels.

Margot Channing was the character played by Bette Davis in the film classic All About Eve.

The alias was used to check into a hotel in Copenhagen, Denmark, in March 2016 according to an email between Bulochnikov, Carey's tour manager Rome Reddick and Epic Records chief of staff Hope Rippere sent on March 24, 2016.

At the time, the singer was on the European leg of her Sweet, Sweet Fantasy Tour, performing in Copenhagen on March 29, while she was still signed to Epic Records.

According to the note, the singer was planning to stay at the luxe Hotel D'Angleterre on her birthday – March 27.

Carey spent the following Christmas in Aspen, Colorado, where she stayed in a $22m five-bedroom AirBnB with her two children and Shakhnazaryan.

Shakhnazaryan also claims Carey used her card to charge a $273,000 worth of items in a two-day spending spree in Aspen Colorado in December 2016

On one of the cosmetic surgery statements, Carey used the alias of Margot Channing, insiders claim. It was also used to check into a hotel in Copenhagen, Denmark, in March 2016 according to an email between Bulochnikov, Carey's tour manager Rome Reddick and Epic Records chief of staff Hope Rippere sent on March 24, 2016

During the trip, it is alleged Carey used Shakhnazaryan's card to charge a $273,000 worth of items in a two-day spending spree.

According to Shakhnazaryan's recent court filing, she 'was damaged in excess of $600,000 for expenditures made at the request of and/or on behalf of DEFENDANTS, and for which she was never reimbursed, and of which Plaintiff is owed.'

A statement for the former assistant's credit card reveals purchases in an array of designer stores on Christmas Eve 2016 totaling $55,545.16 - among them a bill for $4,862.21 at Gucci and $10,895.29 at Dolce & Gabbana.

Another $2,508.44 was spent on a 'women's accessory' at Louis Vuitton and a splurge of $10,135.94 at upmarket menswear store Ermenegildo Zegna.

Mariah had split from her billionaire ex-fiancé James Packer just two months previously.

The day before the spree, the high-spending singer had gone on another shopping trip in Aspen, during which she was photographed.

Again allegedly using Shakhnazaryan's credit card, she spent $16,656.23 at Gucci, $39,681.37 at Louis Vuitton and then bought a relatively modest amount of groceries at WholeFoods for $218.37.

Carey, who completed three shows at London's Royal Albert Hall over the weekend, is no longer working with either Shakhnazaryan or Bulochnikov – parting ways with them in November 2017 and April 2018 respectively.

Both women have since sued the star - Bulochnikov in April 2018, accusing the diva of sexual assault because she was frequently nude in her presence along with civil rights infringements and violating the Fair Employment and Housing Act.

A statement for the former assistant's credit card reveals purchases in an array of designer stores. Allegedly using Shakhnazaryan's credit card, Carey spent $16,656.23 at Gucci, $39,681.37 at Louis Vuitton and then bought a relatively modest amount of groceries at WholeFoods for $218.37

A statement for the former assistant's credit card reveals purchases in an array of designer stores

Another $2,508.44 was spent on a 'women's accessory' at Louis Vuitton and a splurge of $10,135.94 at upmarket menswear store Ermenegildo Zegna. Mariah had split from her billionaire ex-fiancé James Packer just two months previously

In addition to the sex assault claims, Bulochnikov also alleged in court documents the Carey has substance abuse problems and owed her money after terminating her role midway through a contract. This case was settled earlier this year.

Shakhnazaryan filed suit last January ironically after being accused of spending money on Carey's personal credit card. She alleges that the star is guilty of battery and of racially abusing her.

In a statement released to DailyMail.com at the time, Mark Quigley, the attorney for Shakhnazaryan described the allegations against her as 'baseless'.

He added: 'These baseless allegations are an attempt to attack my client's character and deflect attention away from a workplace harassment and wrongful termination lawsuit she filed today against her former employer, Mariah Carey.

'My client never did anything she wasn't specifically asked to do while working in the course and scope of her job as a personal assistant.

'Her lawsuit is about holding her employer accountable for severely inappropriate behavior that caused tremendous stress and emotional turmoil.'

Shakhnazaryan declined to comment when approached by DailyMail.com. Her attorneys Greene, Broillet and Wheeler also offered no comment.

Representatives for Carey and Bulochnikov have also been approached for comment.