Friends of murdered University of Utah student Mackenzie Lueck said this week that the man busted in connection with her slaying was “hunting” women — as it emerged that a former colleague of the suspect once filed a rape complaint against him, reports said.

Ayoola Ajayi, 31, was busted Friday for allegedly killing Lueck and burning her body. He faces charges of aggravated murder, aggravated kidnapping, desecration of a body and obstruction of justice.

Lueck met with Ajayi around 3 a.m. June 17 near a Salt Lake City Park after her Lyft driver dropped her off, authorities have said. Phone records indicate that Ajayi was the last person to communicate with Lueck before she went missing — and both of their phones pinged in that area around that time, authorities said.

The fact that Ajayi requested a soundproof room in his basement, with a secret door and hooks on the wall, in April, indicates that he had something sinister in mind — whether Lueck was the intended target or not, the victim’s friends said.

“[He] was planning on doing this to someone,” friend Kennedy Stoner, a sorority sister, told FOX News Sunday. “I don’t know if it was exactly Kenzie but there was definitely a plan there.”

The friends plan to show up at every court hearing during Ajayi’s trial and “advocate for the harshest, harshest punishment by law,” friend Ashley Fine told the outlet — but they stopped short of pushing for the death penalty, which is still an option in Utah.

They also launched a nonprofit organization called Mackenzie’s Voice, which would help others who’ve been through kidnapping, assault and other traumas to get the support they need.

“I wish I could take all of her pain away from what she went through,” an emotional Stoner told FOX. “I just don’t really know the words to say how I’m feeling.”

Meanwhile, it emerged that back in 2014, a woman who formerly worked with Ajayi at a financial company filed a rape complaint with North Park police, the Salt Lake Tribune reported Monday.

The woman claimed that Ajayi had nonconsensual sex with her while they were at his home, according to the report released to the paper. She immediately told cops she did not want charges filed, and only reported the incident “in case he did the same thing to someone else,” the paper reported.

She had told authorities that she went over to Ajayi’s home, they began “doing stuff,” that “one thing led to another” and “she found herself in a compromising position,” according to the report.

She reportedly told Ajauyi she didn’t want to continue, but he had sex with her anyway.

“She kept saying to me that she felt that it was her fault, because she was not assertive enough,” an officer wrote in the report, obtained by the paper. “I explained that all she needed to do was to say no, and that should be enough.”

But then the woman declined to show up for a follow-up interview and did not cooperate with investigators, according to the report. Authorities never interviewed Ajayi at the time, the paper reported.