Bijoy Krishna Kar, lead investigator for the Bangladeshi national police, told Agence France-Presse on Sunday that Rana and his parents would be among 42 people charged with murder.
The charges initially were to have been filed Sunday, but police said later in a statement that because of some "technical changes," they would delayed to Monday. Conviction could bring the death penalty, Kar said.
More than 2,430 workers were rescued alive from the rubble after six of the factory's nine floors collapsed in the modern world's third-deadliest industrial disaster, after the Union Carbide gas leak that killed 3,787 people in Bhopal, India, in 1984 and the explosion of the Benxihu Colliery coal mine in China's Liaoning province, which killed 1,549 people in 1942.
Separately, the national Anti-Corruption Commission sued Rana on May 24 for allegedly accumulating wealth illegally.
Alex Johnson is a senior writer for NBC News covering general news and technology and religion. He is based in Los Angeles.