The panel charged with building the Minnesota Vikings' stadium is delaying final approval of the contracts so that it can conduct more extensive background investigations and "due diligence" of litigation involving the Wilf family, owners of the team.

The Minnesota Sports Facilities Authority said it has retained Peter Carter of the Dorsey & Whitney law firm to head a group that will conduct the review. It said Carter has tried cases involving racketeering and performed similar investigation for the nation's largest firms.

The review group will include FTC Consulting, an international forensic accounting firm, and will look at Wilf family litigation in New Jersey and perform "extensive background checks" as well as review the investigations conducted by the NFL.

The probe means the Authority will not consider the final agreements with the team as originally planned on Aug. 23, but will schedule a future meeting to do so. "We do not expect this to affect the overall project timeline," the Authority said in a statement.

The delay and new investigation stem from a finding by a New Jersey Superior Court judge in a long-pending civil lawsuit against owner Zygi Wilf and the family's real estate business. The judge said last week the family was guilty of fraud, breach of contract and violations of the state's civil racketeering statute in connection with a real estate partnership. The judge is expected to award damages to the partners.

Gov. Mark Dayton said last week he found the judge's statements  "very, very concerning," and urged the Authority to ensure that the team's commitments to the state are "truthful and accurate."  The Wilfs issued a statement saying the New Jersey lawsuit will not affect the stadium project.

"We're just double-checking everything at this point," said Michele Kelm-Helgen, the chair of the Stadium Authority, on Tuesday. "I think it can be a positive thing, too, so people can be comfortable that we can move on, and they don't have to worry about the financial impact this could have on the stadium."

Kelm-Helgen said the planned October groundbreaking for the stadium is still on schedule.