The investigation into how the fatal fire started is expected to take some weeks.
It is understood that the building where the fire happened was a private residence and not formally linked with the Irish college in Leuven or with the University of Leuven.
Both police and fire services have confirmed that the premises had not been formally registered as a student residence.
However, Leuven is a major university city, and anyone providing private student accommodation must register the building with the authorities and must ensure a fire inspection has been carried out.
The Leuven Institute last night released a statement confirming that the building had been in compliance with all fire regulations.
"Two years ago the building was thoroughly inspected by officials from the insurance company. The building was equipped with all the necessary safety arrangements such as fire alarm, fire extinguishers and escape ladder," the statement said.
The Galway-Mayo institute of Technology has a long relationship with the institute and its students have been going there for at least six years.
Meanwhile, a former resident of the accommodation where the bodies of two Irish students were found told of his "shock" and "devastation" at the tragedy.
Karl MaGee (24) from Irishtown, Mullingar, was on college placement at the Leuven Institute for Ireland in Europe up until just before Christmas.
Mr MaGee said he did not know the deceased but was friends with four students who escaped the blaze.
"There are still four people over there that I lived with and they were still in the house at the time (of the fire)," Mr MaGee said.