ST. PAUL — The former archbishop of St. Paul and Minneapolis, John Nienstedt, interfered with an investigation by an outside law firm into allegations of his misconduct, Minnesota Public Radio reported Friday.

While Nienstedt authorized the investigation in the hope of clearing his name, the results threatened to ruin it. Several of his top advisers gathered privately in April 2014, and read sworn statements gathered by the lawyers that accused Nienstedt of inappropriate behavior, including sexual advances toward priests. Each adviser agreed he should resign.

A few days later, Auxiliary Bishops Lee Piche and Andrew Cozzens traveled to Washington to tell the papal ambassador. But soon after the bishops returned home, the investigation as originally conceived ended, with Piche limiting the probe to allegations of crimes and grave sins. A new law firm eventually took over.

The Vatican announced Nienstedt’s and Piche’s resignations Monday. They stepped down amid an intensifying scandal over how the archdiocese handled cases of clerical sexual misconduct. The archdiocese sought bankruptcy protection in January as abuse claims rose, and prosecutors filed criminal child-endangerment charges against the archdiocese earlier this month for allegedly turning a blind eye to Curtis Wehmeyer, a now-imprisoned former priest convicted of molesting two boys.

In a statement Friday to The Associated Press, Cozzens said Nienstedt has resigned and the archdiocese is moving forward.