At a press conference January 9, State Real Estate Agency manager Martins Tols told journalists a problem with the filters of ventilation and dehumidifying equipment was the likely cause of the damage, though "experts" from both insurance companies and building companies were still investigating the precise cause.
Particularly affected is the famous White Hall, a grand ceremonial room for the reception of foreign dignitaries that is now adorned with a variety of plastic buckets and cloths to catch water dripping from the ornate plaster ceiling through the chandeliers.
Insulation placed between the ceiling and the attic space - where the fire started four years ago - was now sodden, Tols said.
He expressed the hope that the cost of the damage would be covered by insurance - however with litigation worth €4.8m still continuing between the State Real Estate Agency and insurers in connection with the fire, that is by no means certain.
The news is embarrassing to say the least, after the renovated rooms were unveiled with great fanfare just 6 months ago after a €35 million restoration.
Now more remedial work is required.
Riga Castle is the official seat of the Latvian President. Guntis Pukitis, the head of the Presidential office said the work of the chancellery had not been affected but that planned official functions would obviousy need to be moved elsewhere.