Swedish prosecutors have pinned their case against the man on a voice recording from the murder night in 1996. A man who claimed he was drunk called the emergency service to report seeing a man brutally stabbed in central Stockholm. Forensic analyses of the call, however, have not offered significant further information.
"The technical examinations that we have so far been able to perform have not led to strengthened suspicions," prosecutor Erik Wendeby told the TT news agency.
The man's lawyer said the lack of concrete evidence would probably see the case crumble and charges dropped.
"The voice analysis shows no distinct similarities with my client's voice," Clea Sangborn told the Aftonbladet newspaper, which also reported that no DNA matches had been made.
Charges were brought against the now 40-year-old suspect in November, after a breakthrough by the Stockholm police cold case unit. The suspect has denied all involvement in the murder of a 25-year-old man, whose victim was walking home from a party in October 1996 when he was attacked. The victim was stabbed and robbed outside Swartling riding school on Valhallavägen in Stockholm.
Media reported last year that police believed that it was the suspect, who at the time was a 22-year-old economics student, who alerted the emergency services.
"I'm really drunk, I walked past, saw a robbery, it was a guy in a grey jacket," the man told emergency services on the murder night in 1996.
As the phone operator tried to pinpoint the man's location, the caller said he had to return to the scene.
"Listen, I've got to run back and see how he is, I mean he was stabbed many times."
The suspect was released from remand in February, when the prosecutor instead slapped him with a travel ban. Last Thursday, the suspect had his passport returned as restrictions were eased.
"I believe they will have to close down the investigation soon," the man's lawyer commented.