German police on Tuesday arrested a fugitive wanted in the sex slaying of a British college student in Italy, nabbing an African man whose fingerprints had been found at the bloody scene of the sordid crime that has gripped Italians.

Hours later, a Congolese pub owner was freed from jail, where he had been held after being accused of the stabbing by another suspect, the victim's 20-year-old American roommate.

Rudy Hermann Guede, 20, a native of the Ivory Coast, was taken into custody in the western German city of Mainz after police stopped him for riding a Frankfurt-bound train without a ticket, investigators said.

Guede was sought in the sexual assault and fatal stabbing of 21-year-old Meredith Kercher in the house she shared with University of Washington student Amanda Marie Knox in Perugia. Knox and her Italian boyfriend remain jailed in connection with the Nov. 2 slaying. Both have denied any wrongdoing.

Perugia Police Chief Arturo De Felice said he expected Guede to be sent to Italy in "very short time."

"I would like to thank the German police very much because today they arrested the Ivorian man who was wanted in a savage murder in Perugia," said Italian Premier Romano Prodi, who was in Germany for talks with German Chancellor Angela Merkel.

Guede, who once played on a local basketball team in Perugia, had been taken in by an affluent Italian family living in a villa near the hills in the Perugia area.

Diya "Patrick" Lumumba, 38, a Congolese man who owns a pub in Perugia, was released Tuesday for lack of evidence. He had been jailed after Knox told investigators Lumumba had a crush on Kercher and had killed her while Knox was in another room, covering her ears so she wouldn't hear the victim's screams.

But no physical evidence has emerged tying Lumumba to the crime and witnesses have placed him at his bar the night of the murder.

The autopsy found that Kercher had likely died slowly from a stab wound to her neck. She was found on the floor near her bed in her blood-splattered bedroom, half-naked, with a foot sticking out from under bedcovers.

Knox's lawyers said earlier in the probe that their client had given various versions about the killing. The judge's order upholding Knox's jailing on Nov. 6 noted she was confused about the events because she had smoked hashish the night of the killing.

Authorities have said they found Knox's DNA on the handle of a knife believed to have been the murder weapon and Kercher's on the blade. The knife came from the kitchen of a house where Knox's Italian boyfriend, Raffaele Sollecito, lived in Perugia.

The search for Guede was launched after bloody fingerprints were found on Kercher's pillow and on toilet paper in the house. The prints did not match Knox, Sollecito or Lumumba.

Lumumba expressed relief when he was let out of jail Tuesday.

"I thank God who helped me go back home," said Lumumba, who lives in Perugia with his Polish-born wife and young son.

Guede was abandoned by his mother and came to Italy when he was 5, arriving in Perugia with his father, according to an interview in the Rome daily La Repubblica with the Perugia industrialist who took in the Ivorian youth at age 17.

Guede lived in the home of Paolo Caporali, 62, for "seven or eight months," the industrialist said.

"For me and my wife in that period, it was like having one more son — four instead of three," Caporali was quoted as saying.

Guede played basketball with one of Caporali's sons on a team sponsored by the industrialist's vending machine company.

When Guede turned 18, he left the family and turned out to be "a big liar," Caporali said.

Guede skipped school to play video games, and when Caporali found him a job as a gardener at a tourist lodging, he left after a few months without explanation, the industrialist was quoted as saying.

Guede was scheduled to appear Wednesday before a German judge, who will rule whether he can be kept in custody on the Italian warrant, said Karl-Rudolf Winkler, a spokesman for prosecutors in the city of Koblenz.

Italian police traced Guede to Germany through a friend who established Internet contact with the suspect Monday night and chatted with him for hours, Italian investigators said.