A body pulled from Lake Michigan has been identified as missing medical student Ambrose Monye, who disappeared weeks before his graduation, Chicago police confirmed to FoxNews.com Thursday.

A spokeswoman with the Chicago Police Department said the cause and manner of death are under investigation. Monye's body was found Saturday morning and is thought to have been in the water for an extended period of time, according to investigators.

Monye, 28, was last seen around 7 p.m. on April 22. He attended Guadalajara University in Mexico but was in Chicago completing his clinical rotations at Jackson Park Hospital before his graduation on June 1.

No one had seen or heard from Monye since then -- and the family told FoxNews.com there had been no activity on his cellphone, credit cards or email since he disappeared.

Monye had purchased his cap and gown and told his family he wanted to be a cardiologist, according to his younger brother.

Joseph Monye, also a medical student, described his brother last week as soft-spoken and friendly and said he was "always in communication" with his three siblings and parents, who live in Glenn Dale, Md.

"We’re a pretty tight-knit family," said 25-year-old Joseph, also a medical student at Guadalajara University, who, like his brother, was studying in Chicago.

"My mom doesn’t go for two days without talking to us," he said.

Joseph Monye said he entered his brother's locked studio apartment at around 5 p.m. on Sunday, April 24, after he didn't respond to a text message sent the previous night.

There, the younger Monye said he found a reading lamp, air conditioning unit and standing fan turned on. Fresh groceries were stocked in the refrigerator and Monye's laptop was sitting in its usual spot, according to his brother.

The only items missing were the man's wallet and cellphone.

Joseph Monye noted his brother was preparing to take the second part of his U.S. medical licensing exam, but said Ambrose -- who was planning to apply for a cardiology residency -- was well accustomed to high pressure. 

"There was nothing I could think of that would bother him to the extent that he would leave," Monye said.

"His cap and gown graduation photos were already taken," he said. "He wouldn’t jeopardize that for anything in the world. He worked so hard to get to that point."

Monye said he last spoke with his brother on April 21 and described the conversation as "pretty normal."

"It was just him asking me how my rotation is going. He was asking if I was doing OK," Monye said. "I made some jokes with him about the doctors and some nurses. He seemed totally normal to me."