An ongoing investigation led to the arrests Wednesday of three Eastern Contra Costa County men on suspicion of child pornography possession, a Brentwood police sergeant said today.

Evidence from an online child pornography investigation prompted detectives from the Brentwood Police Department and the Contra Costa County Internet Crimes Against Children team, or ICAC, to serve search warrants at homes in Antioch, Brentwood and Discovery Bay on Wednesday.

At each residence, detectives searched the suspects' computers to confirm that they had downloaded child pornography files, Sgt. Tim Herbert said.

Each search turned up multiple files that included "hard-core images of pre-pubescent children or toddlers on up to older kids," the sergeant said.

The search warrant operations ended in the arrests of 42-year-old Justin Lambakis of Discovery Bay, 55-year-old David Larsen of Brentwood and Antioch resident Chad Gengenbach, 36, Herbert said.

None of the men have a criminal history.

All three men were arrested on suspicion of illegally downloading and possessing child pornography files and booked into the Martinez Detention Facility.