The latest report from the Office of the Director of the Authorised Intervention at Tuam (ODAIT) said the remains recovered from the area were discovered in coffins and are currently being forensically examined.
Radiocarbon dating tests have also confirmed the human remains discovered to date are from the premodern era (before 1955).
A statement said “When the radiocarbon dating test results are considered alongside the results of the excavation, evidence collected and human remains recovered, it is ODAIT’s opinion that:
“The 33 sets of infant human remains recovered to date from the red outline area were buried during the period of operation of the Mother and Baby Institution Tuam (1925-61).
“The seven sets of human remains from the area adjacent to the boundary wall (see Second and Third Technical Updates) at the south of the site (green outline) were buried during the Workhouse era.”
The excavation, which got under way on July 14 last year, continues to recover material and objects from the four phases of the 5,000sq m site under examination.
“All evidence recovered is being photographed, catalogued and retained by ODAIT in a dignified and respectful manner consistent with international standards and best practice” the statement continued.
Both machine and hand excavations are taking place at the site of the former workhouse yard, as well as under a tent in the marked area.
The excavation continues to recover material and objects from the four phases of the site’s history.
Objects recovered from the period of the institution include a glass baby feeder.
The excavation is taking place following an 11-year campaign by families of the children who died in the former mother and baby home for unmarried mothers, as well as survivors of the former home, which ran from 1925 to 1961.
In 2016, test excavations at the site revealed there were a significant quantity of human comingled remains of infants.
On Friday OAIT said: "The excavation of the comingled infant remains identified during the 2016/2017 excavations in the subsurface concrete chambers on the site of a historic sewage system in the Memorial Garden presents ODAIT with a unique combination of forensic and engineering challenges.
“To test varying methodologies and ensure adherence to international standards and best practice, ODAIT is constructing an above ground replica of a section of this tank.”
During the reporting period, eight more family reference DNA samples have been taken and delivered to Forensic Science Ireland, bringing the total to 28.
A further 175 people have contacted ODAIT to enquire about providing a DNA sample.
To date, more than 65 cases are being processed for determination of eligibility, with arrangements being made to take their samples in the coming weeks.