NEW ORLEANS (AP) — A businessman convicted in a City Hall corruption case gave prosecutors information about alleged cash payments to former New Orleans Mayor Marc Morial, according to court documents unsealed this week.

In a July memo made public on Wednesday, prosecutors asked the court to note Stan ‘‘Pampy’’ Barre’s cooperation in the corruption probe when it considered his sentence. Barre this month started serving a five-year sentence after pleading guilty to conspiracy to commit mail fraud.

In detailing Barre’s help, prosecutors wrote that ‘‘He provided details of criminal conduct beyond the … conspiracy for which he pled guilty.’’

The memo later said, ‘‘His cooperation included information about cash payments to former Mayor Marc Morial.’’ The alleged payments weren’t mentioned aside from the single reference.

U.S. Attorney Jim Letten refused to elaborate Thursday on when or why the alleged payments were to have occurred.

‘‘Whatever we filed speaks for itself,’’ Letten said.

Morial hasn’t been charged in the corruption case that brought down Barre and others charged with conspiring to skim money from a City Hall contract.

Patrick Fanning, a lawyer for Morial, said Barre is ‘‘trying to throw Marc Morial under the bus, but he doesn’t have any ammunition.’’

‘‘Marc Morial didn’t take any cash payments from anyone. He’s been investigated for over five years by the government. They haven’t been able to come up with any evidence that he did anything wrong, except for something like Pampy Barre to go in and create a lie to try to help himself,’’ Fanning told WWL-TV.

Morial, who served as mayor from 1994 until 2002, is now president and chief executive officer of the National Urban League.

U.S. District Judge Carl Barbier said he unsealed the documents because Barre disclosed details of his cooperation in an article in The Times-Picayune of New Orleans.

In the unsealed memo dated July 10, Letten’s office said Barre’s cooperation led to the conviction of former City Council member Oliver Thomas, who pleaded guilty to a bribery charge last year.

‘‘Barre’s cooperation broke through a previously brick wall of silence,’’ prosecutors wrote, ‘‘and while the government has not been able to sufficiently corroborate all of his information, his cooperation has been of great value.’’

Barre’s attorney, Scott Bickford, declined to comment on the memo.