PHILADELPHIA -- A singer is being sought for questioning in connection with the death of a woman following a cosmetic procedure, police said Friday.

Claudia Aderotimi, 20, died early Tuesday, shortly after receiving buttocks enhancements in a hotel room near Philadelphia International Airport, according to police. The procedure allegedly cost $1,800.

Police say singer Black Madam -- whom they have identified as Padge Victoria Windslowe, 41 -- is believed to be the person who injected Aderotimi with a substance that was supposed to be silicone.

Officers searched Windslowe's apartment for medical supplies, according to a search warrant. She was not home at the time, and authorities are looking for her.

Aderotimi and three other women had traveled from England to undergo the cosmetic procedure in Philadelphia, police said.

A woman who allegedly helped arrange the trip told police that "Black Madam" carried out the procedure, according to an affidavit.

Shortly after the injection, Aderotimi became short of breath and complained of chest pains. She was rushed to a hospital, where she later died, police said.

The preliminary cause of death has been linked to the injection, according to the affidavit.

Underground cosmetic procedures have become a growing cause of concern for health regulators.

Last month, New York officials arrested a woman for allegedly illegally injecting liquid silicone as part an underground business she ran out of her home, according to the Manhattan U.S. attorney's office.

She allegedly charged more than $1,000 for a round of shots and faces up to three years in prison if convicted.

Last year in New Jersey, state health officials launched an investigation into infections related to cosmetic injections after six women were hospitalized for complications.

The women developed symptoms after injections for buttocks enhancement and received surgical and antibiotic treatment, according to the state health agency. All the injections apparently were administered by unlicensed medical providers.

Investigators have had a difficult time tracking these procedures because they are performed by unlicensed providers.

"It's hard to tell how many people are utilizing that [type] of service," said Dr. Tina Tan, a New Jersey state epidemiologist.

Tan has heard reports of caulk and other products being used in the injections, as well as injection substances being purchased outside of medical supply stores, she said.

Not surprisingly, injecting these materials can result in serious health complications and death, she warned.

"In our cluster, these patients had to be hospitalized," she said, adding that injection procedures should be performed by licensed health providers. "We do not recommend going in a hotel room with people who you don't know their credentials."