BOSTON – A Marblehead man pleaded guilty Friday to perjuring himself before a U.S. District Court judge.Yale Strogoff, 73, pleaded guilty to one count of perjury before U.S. District Judge Nathaniel M. Gorton.The prosecutor told the court that had the case proceeded to trial, the government’s evidence would have proven that Strogoff owned a business that purchased and resold scrap metal. In March 2007, Strogoff testified in a pre-trial evidentiary hearing before U.S. District Judge Mark L. Wolf concerning a criminal tax case. During that hearing, the issue of Strogoff’s use of cash for illicit business purposes was raised. Strogoff was asked several times and in several different ways about paying his company’s employees a portion of their weekly wages in cash, to which Strogoff responded six times that he could not recall or remember. In fact, for a period of at least 20 years beginning in about 1980, and continuing until at least the early 2000s, Strogoff’s employees were given weekly pay envelopes, often by Strogoff personally, which contained both a check and cash. The amount of cash was significant, usually about one third of the total weekly wages paid. The practice continued until the early 2000s when Strogoff was first approached by the IRS in connection with its criminal investigation.Gorton scheduled sentencing for Jan. 20, when Strogoff could receive up to five years imprisonment, to be followed by three years of supervised release and a $250,000 fine.The case was investigated by the Internal Revenue Service-Criminal Investigations. It was prosecuted by Assistant U.S. Attorney Mark J. Balthazard of Acting U.S. Attorney Michael K. Loucks’ Economic Crimes Unit.