The third suspect is architect Andris Kalinka. His lawyer Janis Junkers told BNS that the law enforcement authorities had also frozen the assets of Kubs architectural bureau where he practices.
Kubs posted turnover of €643,400 for 2013, a 33.6 percent drop from a year before, while the company's profits were also down but still tallied €126,100.
So far three individuals have been named as suspects in the Maxima store collapse case, and a procedure has been launched to impose restrictions on two legal entities.
The Latvian police on Tuesday decided to arrest two suspects in the case -- civil engineer Ivars Sergets and building inspector Andris Gulbis.
Several roof cave-ins at the Maxima supermarket in the Zolitude suburb of Riga occurred on November 21, 2013, killing 54 people, including three rescuers, and injuring dozens more.
The official investigation into what happened continues.