The families of 18 people who were born with disabilities have taken their bid for compensation to the high court.
Aged between nine and 21, the claimants suffer from a range of conditions, including skin complaints, underdeveloped fingers and eye problems.
They have accused Corby borough council, which is headquartered on George Street in Corby, of negligence.
According to their legal representatives, toxic substances were released when the Corby steel works was redeveloped.
The local authority, however, denies the claims.
Chris Mallender from the organisation states: "For the past five years we have thoroughly investigated every aspect of the claims they are making and we know that there is no link between the reclamation work that was carried out in Corby over a period of 20 years and these children's birth defects."
The hearing, which is scheduled to last ten weeks, continues.