PORTLAND – Police say up to eight convicted sex offenders who should be registered with the city, but aren’t, may be living in Portland.

The people in question are from Portland or listed the city as their address when they were discharged from prison.

In addition, seven offenders have been issued summonses for failing to keep their addresses and pictures current. Three others voluntarily updated their information when they learned police were looking for them.

College interns majoring in law enforcement reviewed conviction data provided by the State Bureau of Identification to determine whether offenders had failed to register with the city and the state.

“These people who get out of prison and don’t register, these are the people we really have to be concerned about,” said Deputy police Chief William Ridge, head of the department’s investigations bureau.

Convicted sex offenders in Maine are required to register with local police when they move into a community, and to keep their information up-to-date.

They also must pay a $25 fee to help maintain the registry, which is designed to give police and the public information about convicted sex offenders, particularly those who target children.

“The legislative reasoning behind having people register is so the public is aware of who they are what they look like and where they live,” said Lt. Vern Malloch, the department’s head of detectives.

There are 65 people currently listed on Portland’s sex offender registry. Officers visit them annually to make sure their addresses are correctly listed, Ridge said.

A 2003 survey found that states were unable to account for 24 percent of sex offenders supposed to be in databases.

And 19 states, including Maine, said they either did not know or were unable to track how many sex offenders were failing to register.