Chinese DNA experts began testing tissue samples collected from unidentified tsunami victims from Thailand in Beijing Sunday, laboratory officials said.

The first batch of 100 samples packed in paper boxes and luggage collected from more than 4,000 unidentified bodies arrived at the Beijing Genomics Institute at the Chinese Academy of Sciences late Saturday.

Outfitted in sterile protective clothing, the DNA experts were busy conducting analyses throughout the day.

According to Yang Xu of the institute's DNA sequencing office, the institute is capable of testing 4,500 samples per day.

More samples are due to be flown to Beijing in a couple of days, Xinhua quoted Captain Ponpasert Ganjanakintr of the Thai Royal Police Office as saying.

He said China's DNA testing standards have reached world levels and China's DNA testing has been offered free of charge to Thailand, for which the nation is grateful.

He said about 400 DNA and forensic experts from the international community have been engaged in the work it the effort will take a month to accomplish.

According to institute officials, the test results will be saved in a database to be compared later to genetic samples from relatives of the possible victim's DNA.

Thai authorities have established centres in morgues where relatives of those missing or unaccounted can have a blood sample taken for possible DNA matching with an unidentified body.

The five-member Chinese DNA testing team arrived in Thailand early December 31 to help with the disaster relief work and has been working in Phuket Island, one of the most affected areas.

Four members of the team returned to China together with the DNA samples on Saturday while another one stays in the area to continue the work of identifying the tsunami victims.