Plaintiffs have filed approximately two private lawsuits a day related to subprime mortgages in the US this year, setting case volumes on course to exceed levels not seen since the aftermath of the savings-and-loan ­crisis, a study has found.

During the first quarter of this year, 170 new civil cases were filed in federal courts, approaching the 181 filings made during the final six months of 2007, according to a review by Navigant Consulting, published on Wednesday. They were overwhelmingly dominated by class-action lawsuits, which accounted for 76 per cent of new cases.