An investigation found the inspectors had renewed licences sometimes without even visiting the factories to check safety conditions in the Rana Plaza building that collapsed on April 24, Labour Secretary Mikail Shipar said.
"The probe has found that the eight inspectors approved and renewed the licences of five factories at Rana Plaza without proper inquiry and supervision," Shipar, the labour ministry's top official, told AFP.
Seven were suspended on Sunday while one has already retired, following the ministry probe into its inspectors who are supposed to check conditions and facilities at the nation's 4,500 garment plants, he said.
The collapse of the nine-storey factory complex killed 1,129 people in a disaster that focused global attention on appalling safety standards at Bangladesh plants.
"In some cases the inspectors renewed licences without visiting the factories. They did it sitting in their offices," he said, adding that approving licences by not visiting plants has become a "trend" in his inspection department.
"One of the factories, Ether Tex, which exports to Western retailers, had been operating without any licences from the factory inspection department since 2008," he said.
A separate investigation whose findings were released on May 22 found that the building's owner was the "main culprit" for the disaster because he violated construction codes.
Investigators have asked the government to prosecute the owner, a low-level official of the ruling Awami League party, for "culpable homicide", which carries a maximum life prison term.
Three of the eight officials fingered during the labour ministry probe had already been suspended for approving licences for a Tazreen Fashion factory north of Dhaka, where a fire killed 111 people last November.
The disasters have sparked an international outcry over workers' safety in the world's second largest clothing manufacturing nation.
After the April 24 disaster, the government launched inspections of all garment factories to try to reassure Western retailers including Walmart, H&M, Tesco and Inditex of improved safety conditions.