AUGUSTA — A bureaucratic oversight resulted in a four-week suspension of payments to pharmacists who provide low-cost prescription drugs to about 3,000 low-income elderly people in Maine, state Department of Human Services officials acknowledged Monday.

“We didn’t pick up on this … until last week,” when druggists began to complain about not receiving their reimbursements, said Rudolph Naples, deputy commissioner for management and budget at DHS.

Naples traced the problem to a failure by DHS officials to update the department’s computer system to reflect technical budget revisions approved by the Legislature earlier this year. The changes should have been made before the last fiscal year ended June 30, he said.

Consequently, when the private firm that is contracted to handle processing of various DHS accounts, Augusta-based Goold Health Systems, forwarded pharmacists’ reimbursement requests to DHS for payment, the computer rejected them.

The bills went unpaid for four weeks, and DHS officials were scrambling Monday to get the $526,000 in back payments in the mail to about 200 pharmacies around the state. They hoped to complete the mailings by Tuesday.

Naples attributed the delay in detecting the problem in part to the departure of a pharmacist consultant who had overseen the program. The consultant retired at the end of June, he said.

Francis Finnegan, deputy director of the Bureau of Medical Services in DHS, acknowledged that the delay in payments reflected deficiencies in the management of the low-cost drug program.

“We need some kind of trip wire here,” he said. “We should be spotting these things immediately.”

The state-funded program provides subsidized prescription drugs for about 3,000 senior citizens whose incomes are low but too high to qualify for Medicaid assistance, Finnegan said. Participants pay a modest amount for the medication and the state reimburses pharmacists for the rest.

Normally, the pharmacists’ requests for reimbursement are paid within a couple of weeks, Naples said. Some of the backlogged requests date to June, he said.

The backlog came to light publicly after Senate President Charles P. Pray wrote to Human Services Commissioner Rollin Ives concerning “misinformation” that Pray was supplied when he called DHS to find out about delays in low-cost drug reimbursements for a constituent.

Pray said a DHS official told him that the Legislature had diverted funds needed for the drug program to other programs. In fact, Pray said, lawmakers approved all the funding that DHS sought for the program and the funding level increased this year.

“I can only assume that the misinformation emanating from your department is the result of intentional policy on your part or of your failure to provide your staff with accurate information,” Pray, D-Millinocket, wrote to Ives.

Ives acknowledged that his department was at fault and played down the significance of the four-week holdup. “Oversights happen,” he said. “That’s not an excuse. That’s just reality.”

As for Pray’s suggestion that Ives intentionally sought to blame the Legislature, “It just proves to me that Charlie Pray needs to be busier during his summer vacation,” Ives said.

Pray, in a telephone interview, said Ives “ought to have a better handle on his department.”

Attempts to reach spokesmen for major pharmacy chains were unsuccessful. A spokesman for LaVerdiere’s Super Drug Stores in Waterville said officials there will not talk with reporters on the telephone. The official at Hannaford Bros. Co. in Scarborough said to be familiar with the situation at that company’s Wellby Super Drug stores was not in his office Monday.