PORTLAND — An Andover man was sentenced Wednesday in U.S. District Court to six years in federal prison for possessing child pornography on computers at his workplace and home.

Jason Littlehale, 42, pleaded guilty to the charge in September. He had been free on $5,000 unsecured bail but was taken into custody immediately after he was sentenced, according to the U.S. Attorney’s Office.

In addition to prison time, U.S. District Judge Nancy Torresen sentenced Littlehale to 10 years of supervised release following his prison terms. The judge also ordered him to forfeit the computers seized at his home.

Littlehale came to the attention of law enforcement in March 2012 when U.S. Homeland Security Investigations received information that images and videos of child pornography had been downloaded to an IP address assigned to Med-Care Ambulance in Mexico where he worked, according to the prosecution version of events to which he pleaded guilty.

The files were viewed at various hours and days of the week between Sept. 23 and Dec. 16, 2011, the document said. The only employee working when the child pornography was viewed was Littlehale. As soon as the ambulance service was made aware of the investigation, Littlehale was placed on paid administrative leave. He later resigned, a spokesman for the service said Tuesday.

In April 2012, investigators seized Littlehale’s home computers and found images and videos depicting children engaged in sexually explicit conduct, according to court documents. One of his home computers included an image of a known child from a series of child pornography that originated outside the state of Maine.

Littlehale faced up to 10 years in prison and a fine of up to $250,000.