A longtime Phoenix Suns employee resigned from the team last month, alleging she became the target of bullying and retaliation by superiors after raising concerns about gender equity and misconduct within the organization, documents obtained by ESPN show.

Melissa Fender Panagiotakopoulos, who began working for the Suns in August 2007, sent a resignation email on May 20 to 16 members of the ownership group, including majority owner Robert Sarver, challenging them to address what she said is a toxic and misogynistic workplace culture.

Her resignation came amid the NBA's investigation into Sarver and the Suns' workplace, which the league launched in November after ESPN published a story detailing allegations of racism and misogyny in a sometimes hostile and toxic workplace during Sarver's 17-year tenure as majority owner. Sarver has denied the majority of the allegations in ESPN's reporting.

In her resignation email, Panagiotakopoulos wrote that she was sending it to "key stakeholders" to "make certain this group can influence positive change."

She did not specifically reference any issues with Sarver, or name any individual employee.

Panagiotakopoulos most recently held the title of senior premium experience manager, a position responsible for helping to generate revenue from high-level clients. She held that position from April 2014 until her resignation.

In the email, which was also sent to the Suns' head of human resources, Panagiotakopoulos offered a list of allegations, saying that "each of these points create the culture and make up the character of our leadership."

She alleged that there were "inherent conflicts of interest with managers' ability to receive commissions, cherry pick deals, revise suite lease terms to line their own pockets, and operate in a different manner than the rest of the sales organization with no true consistent systems or oversight."

She also alleged inequities and gender discrimination, writing, "Is it a coincidence that I have been the only mother in the entire sales organization for the last 15 years? Is it because certain males were being paid more in equivalent roles?"

And she alleged issues with human resources' "ability to stay relevant and exert influence over C-suites - the lack of follow-up, ability to resolve conflict or true concern for employee well being."

"We have been made aware of allegations by a former employee and are investigating them, consistent with our Respect in the Workplace Policy," the Suns Legacy Partners organization said in a statement provided to ESPN. "The Phoenix Suns are committed to creating a safe, respectful, and inclusive work environment free of discrimination and harassment, and we do not tolerate retaliation for the reporting of alleged misconduct."

Despite the team's recent on-court success, Panagiotakopoulos wrote the organization has "never been more dysfunctional, and the culture is rapidly eroding."

Panagiotakopoulos, who declined to comment for this story, also wrote that she had previously voiced similar issues, including gender discrimination, in a memo to the team's human resources department on Nov. 10 -- less than a week after ESPN's initial story was published.

That note, which was attached to the email sent to Suns ownership on May 20 and obtained by ESPN, said, in part, "Over many years, it has become clear to me that the Suns organization does not place the same value on developing women in its workforce, or even on ensuring they are treated equally as compared to their male counterparts."

In that memo, Panagiotakopoulos alleged that a male colleague with similar tenure but less responsibility was paid at a higher rate and permitted to work from home.

"As a working mother, when I requested the same flexibility, I was denied," she wrote. "I have observed these kinds of inequities throughout the Suns organization, and I have personally experienced the kind of gender-based misconduct described in recent media reports. And when I attempted to share my concerns with HR and leadership (including individuals at the highest level), I was dismissed - and once was even told to 'take a cold shower.'"

In her resignation, Panagiotakopoulos referenced the November memo, writing, "Since that confidential interaction with senior leadership, HR and legal, there has been a consistent retaliation and bullying by my direct leadership."

"Among other things," she wrote, "they excluded me from client dinners, scrutinized my every move, decision, and email with excruciating levels of micromanagement."

"My job has grown more intolerable and toxic than ever," Panagiotakopoulos said.