PITTSBURGH -- Allegheny County Judge David Wecht was called as a witness Friday before a federal grand jury that's investigating his father, Coroner Dr. Cyril Wecht.

Channel 4 Action News reporter Bob Mayo said federal investigators are digging for evidence of whether Dr. Wecht mixed his private business with his public office, and the probe is pulling his family before the investigative grand jury.

Judge Wecht and his wife, Valerie, spent about 90 minutes under separate grand jury questioning Friday, Mayo reported. The judge declined to comment as he left court.

Judge Wecht and his wife cooperated fully, answered all questions and supplied subpoenaed materials, according to his attorney.

Published reports claim that investigators want know if Judge Wecht and his wife ever did work for Dr. Wecht's private firm, and if coroner's deputies played any part in Judge Wecht's campaign for register of wills seven years ago.

Retired deputy coroner George Adamson also testified. He said the grand jury asked whether he and others used county cars to chauffeur for the coroner's private business and relatives, including the coroner's wife.

A woman who said she works for Dr. Wecht was the fourth grand jury witness in Friday's session. She would not identify herself to Channel 4 Action News, nor disclose the reason she was subpoenaed to testify.

Dr. Wecht's son, Benjamin, has also been subpoenaed to testify. He works at the Wecht Institute at Duquesne University.