A man who survived vaccine trials as a child growing up in a notorious Catholic orphanage says he believes there are more children secretly buried in a cemetery that was attached to the project.

David Kinsella, 59, spent the first four years of his life St Patrick's on Dublin's Navan Road – one of nine 'Mother and Baby Homes' that operated in Ireland in the last century, accommodating women who fell pregnant out of wedlock and their offspring.

A series of revelations have exposed that some of the homes subjected the children to vaccine trials at the behest of major pharmaceutical companies. They were separated from their mothers at birth, who would then typically work for a year to pay back the Catholic church.

David was hospitalised six times and required a blood transfusion after he was pumped full of drugs at the Navan Road facility, he told the Irish Mirror. He could not talk or walk when he was adopted a the age of four.

Infant mortality rates at the home were high as a result of the drug trials and other mistreatment of the children, including chronic malnutrition. It is estimated that between 2,000 and 3,000 children died there between its opening in 1904 and closure in 1985.

Many of dead were buried in a special mass grave in Glasnevin Cemetery, known as an 'Angels Plot', but it has also been revealed that several hundred were donated to medical institutions for research purposes. A memorial is taking place on Sunday 13 August at the plot in Glasnevin and David is attending.

However, he is convinced that there are more babies buried secretly elsewhere in the grounds. He told the Mirror: "I don't believe all of the infants have been found yet. The grounds need to be searched properly. There are more babies that were secretly buried there.

"If it was done in Tuam [another Mother and Baby Home], it obviously was the norm and I can't see how it was any different in St Patrick's."

More women and children passed through the institution than through any the other homes, according to thejournal.ie. Bon Secours Mother and Baby Home in Tuam, Co Galway, has probably received the most media attention of any of the orphanages after a 2012 discovery by a local historian that almost 800 children had died there between 1925 and 1961.

The scandal of this discovery, and others like it, has inflicted a deep scar on Irish society and the Catholic Church.

A shrine in Tuam, County Galway, erected in memory of up to 800 children who were allegedly buried at the site of the former home for unmarried mothers run by nuns Getty