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The mother of a University of Pennsylvania student who killed herself in 2013 by ingesting soluble cyanide crystals that she allegedly bought on Amazon is suing the school and online retailer.

Sujata Singh filed the lawsuit against Amazon and the University of Pennsylvania in late July, about two and a half years after her 20-year-old daughter, Arya Singh, committed suicide in her dorm room.

The lawsuit alleges that the nursing student was sexually assaulted when she was a freshman at the University of Pennsylvania, and said the school allowed the accused assaulter to remain in the same dormitory as Singh. The alleged assaulter wasn’t punished by the school, according to the suit, which was posted on the legal news website Law360.

Nursing junior Arya Singh

Sujata Singh is suing the school for negligence, claiming that professors and administrators ignored issues that her daughter was experiencing as a result of the alleged sexual assault. The suit said that school was aware of behavioral problems that might stem from a sexual assault because college administrators received a letter from the Department of Education that outlined such complications.

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The lawsuit also said that the school never contacted Singh’s sister or mother about the troubled behavior the student was exhibiting, even though she told numerous campus authorities and advisors about the alleged assault.

Singh also reported the alleged assault to the University of Pennsylvania Police Department and the Philadelphia Police Department investigated the alleged assault and each created a report, the lawsuit said. Neither police department could immediately confirm such reports were made Friday.

Singh’s grades plummeted, she was arrested for alcohol intoxication and was the subject of more than one academic and misconduct investigations, according to the claim. But the suit claims "University employees’ conduct toward her was unsympathetic, hostile and at times, vindictive."

Singh was told on Feb. 8, 2013 that she had to vacate campus in the midst of a misconduct investigation against her, since the investigation barred her from registering for classes, the lawsuit said. Hours later, she killed herself by ingesting soluble cyanide crystals, according to the lawsuit.

A University of Pennsylvania spokesman, Ron Ozio, also declined to comment on the pending lawsuit.

Singh bought the cyanide through a Thai company on Amazon in early December, according to the lawsuit. Amazon processed the payment and kept a portion of the sale price, the complaint said.

"Despite having a policy and procedure of prohibiting through its website offers and sales of prohibited items, illegal products and banned hazardous substances in the United States, including but not limited to cyanide products, Amazon failed to enforce that policy and procedure," said the lawsuit.

Amazon did start preventing the sale of cyanide on Feb. 2, 2013, but by then it was too late. The lawsuit said 51 other people purchased cyanide on Amazon before Singh, resulting in the deaths of 11 purchasers "within weeks of sale."

Sujata Singh is suing Amazon for negligence and failing to prevent the Thai company, which is also listed as a defendant in the suit, from selling cyanide.

An attorney for Amazon, Andrew K. Garden, told NBC News that Amazon does not comment on pending litigation.