MARTINEZ -- A 52-year-old Brentwood man plead not guilty Friday to molestation charges against a 10-year-old boy over a six-year period starting in 1991.

The Contra Costa District Attorney's Office charged Gordon Thomas Blake this week with 15 felony counts of sexual molestation. The alleged molestations took place in Blake's home and at a community pool, and continued until 1996, said deputy district attorney Ryan Wagner.

A preliminary hearing is scheduled for 8:30 a.m. April 9 in Pittsburg, Wagner said.

Police began the investigation in January when the victim came forward. Police say there could be other victims because Blake had contact with many children at the community pool at 180 Cottonwood Common in Brentwood during those years.

Blake was arrested Tuesday and is being held on $1.4 million bail.

Anyone with additional information about this case can call police investigators at 925-809-7759.

Staff writer Kristin J. Bender contributed to this story. Contact Paul Burgarino at 925-779-7164. Follow him at Twitter.com/paulburgarino.