The state agency in charge of protecting Minnesota’s vulnerable adults and children says it’s struggling with a growing backlog of maltreatment allegations and needs more investigators to cope.

One measure of that workload — the number of reports assigned by the Department of Human Services for field investigations or death reviews — rose 10 percent, to 1,053, in the year ending last July 1. There were 883 such cases in the year before, the Star Tribune reported Tuesday.

In a report released Monday, the department asked the Legislature for additional investigators to help tackle a backlog that has nearly doubled to 724 cases in the last 18 months.

DHS Inspector General Jerry Kerber said the governor’s budget proposal would add about a dozen positions, including eight investigators. The new jobs would come primarily from higher fees on businesses regulated by the DHS. That proposal has run into resistance at the Capitol.

“It’s a reasonable expectation of the public that we do these investigations of alleged maltreatment . and that we do it in a reasonable time frame,” Kerber said. “We have that expectation of ourselves. We can’t do it with magic. We need resources to do that work. We are hopeful the Legislature will recognize that.”

The agency receives 4,500 to 5,000 maltreatment allegations and other licensing reports each year. About 1,000 are assigned for field investigations or death reviews. Last year, the number of assigned cases grew, adding to a backlog that had been growing for several years.

Some 60 percent of the allegations involve adult foster care homes and programs that serve people with disabilities, including mental illness and mental retardation, as well as some physical challenges. About 17 percent involve child-care centers or adolescent treatment programs.

The agency is required to report its backlog, as well as other trends that affect the safety of vulnerable adults in DHS programs, to the Legislature annually. But the last report was issued more than two years ago. The agency vowed to correct that reporting problem after the Star Tribune identified it in a story earlier this month. Kerber said his office will begin issuing the maltreatment report annually, probably each August.

The report issued Monday showed more than 1,100 substantiated reports of maltreatment in the past five years, or about 225 per year. The report said the number of neglect cases is increasing, while cases of abuse are generally decreasing.