“We have been working intensively with the investigation and now need until Thursday next week to complete the preliminary investigation,” prosecutor Daniel Suneson said in a statement.
The 30-year-old artist, whose real name is Rakim Mayers, was arrested on July 3 shortly after midnight along with three other people after a street fight on June 30. One of them, Mayer's bodyguard, was released later in the week.
On July 5 the Stockholm District Court ordered that Mayers should be kept in custody while the case was being investigated, as he was considered a “flight risk”.
The court had given the prosecutor until July 19 to decide on whether to press charges.
According to the Stockholm District Court, new hearings for ASAP Rocky and the two others in custody would be scheduled later on Friday.
The Swedish Prosecution Authority meanwhile said a new prosecutor, Daniel Suneson, had taken over the investigation from Fredrik Karlsson as it was the “vacation season”.
Brawl caught on video
Mayers' lawyer Slobodan Jovicic told Swedish tabloid Expressen last week that the key to having the detention ruling reversed in a new hearing was to either find evidence that Mayers was not a “flight risk” or argue it was unfair to keep him in custody if the investigation was prolonged.
“The court could hold the position that two weeks is okay, but not more than that,” said Jovicic.
The rapper has claimed he was acting in self-defence, reacting to the provocations of two young men who harassed and followed him and his entourage.
Part of the incident was captured in a amateur video published by US celebrity news outlet TMZ.
In the video, the rapper, who was in Stockholm for a concert, can be seen throwing one of the men into the street and then aiming several punches at him while he is down.
Mayers posted his own videos on Instagram on July 2 which he said showed the lead-up to the clash.
In those, the young man can be seen arguing with the musician over a pair of headphones, and the artist repeatedly asks the man and his friend to stop following them.
One of the young men can also been seen hitting a member of the artist's entourage.
According to the Swedish Prosecution Authority a separate investigation into assault and harassment committed by the plaintiffs is also ongoing.
Fellow artists like Post Malone, Sean “Diddy” Combs, Nicki Minaj, Meek Mill and Justin Bieber have taken to social media to voice their support for Mayers.
Some artists have singled out Sweden: rapper Tyler, The Creator tweeted “no more sweden for me, ever”.
An online petition called #JusticeForRocky has garnered more than 600,000 signatures, and posters with the words “Free ASAP Rocky ASAP” have been put up around the Swedish capital.
US media reported Thursday that reality television star Kim Kardashian West, who has recently campaigned for criminal justice reform, had contacted the White House over the case.
Several members of the US congress have also called for the rapper's release.
Former US ambassador to Sweden, Mark Brzezinski, told Swedish newspaper Dagens Nyheter that he had contacted the country's foreign ministry and the Swedish royal family, calling the rapper's arrest a matter of “racial injustice”.
Sweden's foreign ministry responded by saying the Swedish justice system was independent from the government.
Fans of the rapper have also been enraged by claims that the artist was being held in “inhumane conditions” –allegations made by the artist's manager as well as a TMZ report quoting anonymous sources.
However the director of the remand prison where he is being held quickly denied the claims, adding that the facility had been recently refurbished.