Dhaka, Bangladesh (CNN) -- The death toll has climbed to more than 620 in last month's collapse of a Bangladeshi garment factory building, police said Sunday.
As authorities searched through the rubble of what has become the nation's worst industrial disaster, the stench of decomposing bodies filled the air.
On Sunday night police said at least 626 people were confirmed dead, and crews were expected to continue searching for bodies for a few more days.
Family members of victims remain camped nearby, awaiting news of missing loved ones.
The April 24 collapse of the Rana Plaza Building in Savar, a suburb of the capital, Dhaka, is the most serious disaster to strike Bangladesh's garment industry.
Preliminary results of a government inquiry into the building collapse found that "heavy machinery and high-capacity generators" were "largely responsible," the state-run Bangladesh Sangbad Sangstha News Agency reported.
"During the inquiry, we have found that use of substandard materials during the construction also contributed to the building collapse," the leader of the inquiry, Main Uddin Khandaker, told BSS.
Bangladesh's $20 billion garment industry accounts for 77% of the country's exports.
Among those caught up in the finger-pointing after the building collapse disaster are Western retailers and clothing brands that Bangladeshi suppliers say put heavy pressure on prices, resulting in bad pay and conditions for workers.
CNN's Tom Watkins contributed to this report.