(CNN) A 7-year-old girl who underwent a painful genital mutilation procedure told federal investigators that after a doctor completed the process, she was rewarded with a piece of cake for "doing good."

Court documents obtained by CNN contain that account, along with other details in the cases of three medical professionals now facing charges in the first federal female genital mutilation case in the United States.

The father of the girl -- one of two 7-year-olds who underwent the procedure on the same day -- told investigators, "that if they knew what would come of it, this would never have happened," according to the documents.

The documents identify the parents, but CNN is not naming them to protect the child's identity. While three medical professionals face trial in the case, no charges have been filed against the parents.

This month, two Michigan doctors and the wife of one of the doctors were charged with performing a banned female genital mutilation procedure on the two little girls, both from Minnesota.

Detroit emergency room physician Jumana Nagarwala, 44, was arrested April 12 and is in jail awaiting trial after a federal judge deemed her a flight risk and a threat to the community. Dr. Fakhruddin Attar, 53, and his wife, Farida Attar, 50, were arrested Friday at their medical office in Livonia, Michigan, west of Detroit. They are accused of assisting Nagarwala in the procedures.

Both girls, their families and the three defendants are members of the Muslim Dawoodi Bohra sect in Minnesota, according to a criminal complaint filed in the case against Nagarwala.

Investigators described it as a "religious and cultural community" they allege practices female genital mutilation -- a painful surgical procedure to remove part of the clitoris or clitoral hood to suppress female sexuality.

The defendants have not entered pleas, but attorneys for all three have argued their clients are not guilty of all charges.

In the wake of Nagarwala's arrest, authorities in Hennepin County, Minnesota, immediately filed a protection petition on behalf of one of the young victims, and that petition included the girl's statements.

Genital mutilation victim: It 'hurted a lot'

According to court documents filed on April 13 in Hennepin County:

In February, the girl was driven to Michigan to receive the genital mutilation procedure. The girl told investigators she traveled "with her mom, a friend and her friend's parents."

"They went to see a doctor and (the girl was told she) cannot tell anyone about that," said court documents.

The girl told investigators her mom told her to keep the procedure a secret.

She said her friend also went to the doctor's office and "the doctor made her cry."

The girl told investigators there were three people in the office, "one to clean up and two to hold (the child's) hands."

In a criminal complaint filed against Nagarwala, investigators said that federal investigators had the doctor's office under surveillance, based on previously received information, when hey saw the two girls and their mothers arrive at Attar's Burhani Medical Clinic. Attar, his wife and Nagarwala were already inside.

Regarding the actual procedure, the girl told investigators, she felt a "little pinch," and then the area was cleaned. The next day, the girl said, it "hurted a lot." The girl described the pinched area as "where we go pee."

The girl told investigators, the doctor gave them "white stuff to put on it and then they got cake after because the doctor said "they were doing good." The girl said she felt pain and burning in her genital area.

The girl said three days passed before she felt better and no medicine was needed. She said the doctor had told them "no bikes and no splits for three days."

Investigators said the girl's father was aware of where his wife was going with their daughter because she texted him.

Girl taken from home

On April 11, the girl was removed from her parents home for 72 hours, according to the court documents. During this time, medical exams revealed that her "labia minora was either surgically removed or the minora was sewn down."

The girl was allowed to return to her parents, Hennepin County district attorney's office spokesman Chuck Laszewski told CNN.

As a condition for her return, the parents were required to provide the girl with medical and psychiatric care and allow a social worker to visit their home, said Laszewski.

CNN's calls to the parents were not returned.

Second girl in foster care

Forty miles north of Hennepin County, in the neighboring Anoka County, a separate child protection petition was filed on April 13 on behalf of the second 7-year-old girl, according to district attorney's office spokeswoman Elizabeth Mohr.

On April 19, a judge ordered the case and all files (except the order) be sealed and the hearings be confidential, Mohr told CNN.

According to the order, "Child 1 entered foster care and an Emergency Removal Hearing was held due to her parents' decision to submit the child to an unnecessary medical procedure."

Due to the confidentiality of the case, it is unclear if the child has returned home to her parents.

A crime or a religious practice?

Leaders of the Dawoodi Bohra sect's Michigan mosque released a statement Friday saying they are offering assistance to investigators, according to the Detroit News.

"Any violation of US law is counter to instructions to our community members," the statement said.

"It is an important rule of the Dawoodi Bohras that we respect the laws of the land, wherever we live," the statement continued. "This is precisely what we have done for several generations in America. We remind our members regularly of their obligations."

CNN's calls to the mosques attended by the parents and the defendants were not returned.