A Bangladesh expert said Monday he has given up hope of identifying 112 victims of the Rana Plaza factory collapse, almost a year after one of the world's worst industrial tragedies.

The garment factory complex on the outskirts of Dhaka collapsed in April last year, trapping thousands of workers who stitched clothes for Western retailers.

Rescue work ended three weeks later with 1,129 bodies recovered from the ruins of the nine-storey complex.

Authorities buried more than 300 victims whose bodies were so badly damaged or decomposed that they were beyond recognition, but collected their DNA samples to help verify any compensation claims.

Sharif Akhteruzzaman, head of the National Forensic DNA Profiling Laboratory, said his experts have now identified 200 of those victims after matching their DNA samples with those of living relatives.

"Of the 322 people, we have now identified 200 people. Of them 157 were identified earlier and 43 this month," Akhteruzzaman told AFP.

But Akhteruzzaman said the lab could not identify more than 100 victims, despite reanalysing their samples and trying to match them.

"We don't have any hopes for these 112 bodies as they did not match with any of the 549 people who've come to us for their missing relatives."

Formal identification means families can claim compensation for the tragedy, amid anger that authorities were not doing enough to help those left behind.

Akhteruzzaman has previously raised concerns about the quality of the DNA samples which were collected.

Akhteruzzaman also said the lab was analysing human remains recovered at the site in recent months to try to identify them, although it was unclear how many new victims have been found.

Police said in December they had recovered remains after street children spotted bone fragments while rifling through debris at the site.

The recovery has reinforced accusations by labour groups that the operation to rescue workers and retrieve bodies ended too quickly, and that the death toll could be higher still.

The tragedy highlighted the appalling safety conditions in the world's second largest garment industry after China, and forced Western retailers and the government to promise factory safety inspections.

Bangladeshi and international labour unions have criticised the government, factory owners and Western retailers for not swiftly and adequately compensating victims and their families.

The government has said it has paid money to families of around 800 victims, including about 40 survivors who lost limbs.

But authorities have delayed compensating the rest, citing a lack of identification, a task made more difficult by inadequate payroll records kept by the factory's managers.