Police began questioning two Lithuanian brothers aged 31 and 35 on “reasonable suspicion” of murdering the teenager on Friday night and interrogated a woman accused of “harbouring a criminal” in connection with the case.
The deputy chief prosecutor, Lars-Göran Wennerholm, announced on Tuesday that there was now a “stronger degree of suspicion” surrounding all three suspects, who deny the accusations against them.
Skaraborg District Court later ordered the two brothers to be remanded in custody for another fortnight under the stronger degree of suspicion. It ordered police to extend the woman's detainment by another week under the weaker “reasonable suspicion”.
Swedish law states that suspects formally arrested under “reasonable” and “stronger” of suspicion can be be held for a further one or two weeks, respectively, and potentially an extended period after that.
Wennerholm told the TT news agency that his team had “worked intensively over the weekend” and had reached their decision based on “the big picture of everything we have found during the investigation”.
He added that prosecutors were still waiting for other forensic evidence including DNA sample results.
IN PICTURES: Huge hunt for missing Swedish teen
Lisa Holm (left) and flowers left outside a church in Skövde on Sunday. Photo: TT
Lisa Holm disappeared after working a shift at a cafe on June 7th in Lidköping, a small town in a rural area north east of Gothenburg, and is close to two of Sweden's largest lakes.
On Monday police closed off a new area of the ridge where Lisa Holm's body was found as they continued their investigations into the killing.
More than 7,000 people disappear in Sweden every year, according to the charity Missing People, but the search for Lisa Holm was the biggest in recent years and captured high media attention.
Around 900 volunteers joined the hunt for the teenager, searching woodland, fields and buildings in the region.
On the Facebook page for regional police force Östra Skaraborg, a staff member wrote that the case had touched officers, with one seen “shaking and crying behind an outbuilding” and a police dog handler “burying his face into the dog's fur” when the news emerged on Friday that the teenager's body had been found.