Gwinnett County District Attorney Danny Porter says he needs another investigator to help him keep up with allegations of public corruption.

Porter has asked the county to pay for a new position for an assistant chief investigator to oversee “public integrity” cases, which he said have been on the rise in recent years.

Porter made the request last week as part of his 2013 budget proposal. County Commission Chairwoman Charlotte Nash, who will prepare the proposed budget, said she hasn’t “added up the numbers” on the district attorney’s request. But she thinks it has merit.

“I think there’s some validity to the idea of saying, ‘This is so important we’re going to dedicate a full-time person in the district attorney’s office,’ ” Nash said.

Public integrity has been a big issue in Gwinnett politics in recent years.

In 2010, following an investigation into county land purchases by The Atlanta Journal-Constitution, a special grand jury concluded that Gwinnett spent too much in deals that benefited the political allies of commissioners. The jury charged then-Commissioner Kevin Kenerly with bribery, claiming he accepted or agreed to accept $1 million to arrange for Gwinnett to buy land. Kenerly denies the charge, which is still pending. Jurors also considered a perjury charge against then-Chairman Charles Bannister, who resigned to avoid prosecution.

And in May Commissioner Shirley Lasseter resigned after pleading guilty to a federal bribery charge. She and three other defendants are cooperating in a federal corruption investigation, and more charges are possible.

Porter said he takes two or three public integrity cases a year to a grand jury and investigates many more. They often don’t result in criminal charges, but Porter said his office must still investigate them.

The allegations include bribery of elected officials and wrongdoing by police officers. Though he couldn’t cite specific statistics, Porter said he’s seen an increase in allegations as the high-profile cases have gained attention.

The investigator also would assist with administrative duties. Porter said the position would allow him “to focus efforts on these investigations that are now being assigned to other investigators in addition to their regular workload of armed robberies and everything else.”

The position would cost about $122,000. Whether Gwinnett’s budget realities will permit the new expense remains to be seen. Nash said she expects county revenue to decline again next year as real estate values affect property taxes. But she’s not ruling out the position.

“I think there’s some validity to the request for that type of position,” she said. “I think there’s a message that can be sent.”