Nassau prosecutors seated a panel of special grand jurors Wednesday to investigate public corruption in the Town of Oyster Bay, multiple sources with knowledge of the case said.

The special grand jury will meet on a regular basis and is expected to hear evidence for several months as prosecutors seek an indictment, the sources said.

Some of that evidence includes wiretaps from investigators’ electronic surveillance efforts, a source close to the case told Newsday.

A judge from Westchester came to Mineola to swear in the panel to avoid an appearance of any conflicts of interest locally, sources said.

A spokesman for Nassau District Attorney Madeline Singas declined to comment.

The empaneling effort began about an hour after Singas held a news conference to support proposed state legislation that would toughen penalties for the crime of official misconduct and make it illegal to lie to prosecutors or their investigators.

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The special grand jury proceedings in Nassau, which by law are secret, follow October’s federal corruption indictment of former Town of Oyster Bay Supervisor John Venditto, along with Nassau County Executive Edward Mangano and his wife, Linda Mangano. All three have pleaded not guilty.

Singas’ office assisted federal officials in that probe, cooperation she alluded to at Wednesday’s news conference on the effort to increase public corruption penalties.

In the federal case, Edward Mangano and Venditto are accused of receiving bribes from a Long Island restaurant owner in exchange for Nassau County contracts and the Town of Oyster Bay guaranteeing millions in loans. They face charges including bribery, conspiracy and honest services wire fraud.

The businessman allegedly gave Linda Mangano, who is accused of charges including conspiracy to obstruct justice and making false statements, a lucrative no-show job.

Venditto resigned as town supervisor last month.

On the day of those October arrests, Singas issued a statement saying the “charges and our investigations underscore the importance of passing strict ethics and oversight reforms to protect taxpayers.”

She then added: “I renew my call for immediate action to drain this cesspool of corruption and restore confidence in the integrity of our government.”

Singas made combating public corruption the hallmark of her campaign when she won election to a first term as Nassau’s top prosecutor in late 2015 during a race in which many viewed her as an underdog.

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The formation of the special grand jury also follows the 2016 federal conviction of now-former Town of Oyster Bay Planning and Development Commissioner Frederick Ippolito in a tax evasion case.

Ippolito, 78, was sentenced to 2 years and 3 months behind bars, which he’s serving at a federal prison in Massachusetts with medical facilities for infirm inmates. His scheduled release date is in November 2018, records show.

In January 2016, Ippolito pleaded guilty to evading taxes linked to $2 million in outside consulting fees he collected while serving as a town commissioner.

Federal prosecutors said the money was from paving contractor Carlo Lizza & Sons – a contractor that did town business – along with the Lizza family trust. Ippolito had worked a full-time job for the contractor before his job with the town.

Before Ippolito’s September 2016 sentencing, U.S. District Court Judge Leonard Wexler delayed the proceeding for two months after saying in court that “there is something rotten in the Town of Oyster Bay” and demanding more answers about the case before meting out the former public official’s punishment.