Alleging defamation, conspiracy theories and threats by a federal official, former South Jersey Economic Development District Executive Director Gordon Dahl has threatened to sue the district, Atlantic County, and representatives of the NextGen Aviation Research and Technology Park.

Dahl also demanded more than $1 million in settlement costs.

A six-page letter detailing his demands was sent to representatives of the SJEDD prior to the board’s unanimous vote of “no confidence” in Dahl’s abilities Monday night. In the letter — obtained Thursday by The Press of Atlantic City — Dahl’s Mount Laurel-based attorney, Kevin Costello, said Dahl would pursue litigation unless the board dropped the vote and instead moved to negotiate a settlement. Costello could not be reached Thursday.

“The entity and its handlers can certainly have what it and they wish — my client’s departure — but it must be done appropriately and fairly, given what my client would be expected to give up,” the letter states. “The fact that my client has also been the recipient of threats, intimidation and coercion by a federal elected representative with apparent ties to one or more of the parties receiving this letter and/or one of the parties mentioned herein, only enhances the reasons why the matter ought to be resolved clearly and finally and early.”

The official is not named in the letter.

Dahl was fired Monday and has not made any comments to The Press since early March. His decision-making was questioned after it was discovered that the district, which was two years behind on audits, incurred hundreds of thousands of dollars in debt while leading the installation of infrastructure at the NextGen park. Meanwhile, Dahl’s salary increased by more than 40 percent between 2006 and 2011 with no documentation showing that he ever received proper approval for the raises.

The letter, dated March 30, states that Dahl believes Atlantic County, representatives of the park’s board, and Ford-Scott & Associates auditors have participated in “a conspiracy of defamation and tortuous interference.” He believes the entities were attempting to make the NextGen park site appear less valuable to allow Northfield-based New Vistas, a conditional developer selected by the park’s board, to make a significant profit on the property.

The district has been under pressure to transfer the lease for the park’s land to the park’s board. Dahl refused — initially with the support of his board — to turn over the lease unless the district was reimbursed for $858,000 spent on the project that is not reimbursable under grant agreements. The park’s board would not agree to that arrangement, which spurred Dahl’s assertions that those involved were attempting to make the property appear less valuable.

Atlantic County Executive Dennis Levinson said Dahl’s claims that anything improper took place are absolutely untrue.

“That’s a pretty wide-ranging conspiracy, if that’s what he thinks,” Levinson said. “Obviously Gordon Dahl will do what he believes is best for him, and we will do what we believe is best for the taxpayers.”

Ron Esposito, executive director of the NextGen park, declined to comment on the letter, citing the pending litigation.

SJEDD attorney Paul Baldini said he can’t speak to the validity of any of Dahl’s claims, given that Baldini has only been the organization’s attorney since February. The SJEDD has not had any direct contact with Dahl since Monday’s vote, but the district has been in contact with Dahl’s attorney, he said. Despite the claims in the letter that Dahl will immediately pursue a lawsuit, Baldini said he believes a negotiated settlement is still an option.

“Given that at the last meeting I was requested by the district to explore the position of resolution short of litigation — and that is also my philosophy — I believe there will be further discussions prior to any litigation,” Baldini said.

Prior to the board’s vote of no confidence, Dahl was seeking a $1,055,000 settlement, according to the letter. That figure includes his salary for the remainder of 2012, $182,000 as compensation for a pension hit, $30,000 for health insurance for two years and $750,000 in damages.

“Damages, I can assure you, are significant and becoming more so as my client’s excellent and distinguished career of public service comes to an embarrassing and ignominious end,” the letter states.

Dahl has led the district since 1987. His contract renews automatically and does not require him to undergo performance evaluations. The letter states he will claim breach of contract, as no notice was given of any intention to terminate the arrangement. The contract states that it renews each February unless one party provides 30 days written notice of the intention to terminate.

The letter consistently refers to the park’s board as “the Atlantic County Not-For-Profit,” a description that is inaccurate. The park’s board, of which Dahl was a member, has representatives from various agencies involved in the project, including Atlantic County, The Richard Stockton College of New Jersey, the state Economic Development Authority and the Casino Reinvestment Development Authority.

It is unclear why the description is used throughout the letter. In multiple interviews this year with The Press regarding the potential lease transfer, Dahl referred to the park’s board and Atlantic County interchangeably, saying Atlantic County was the driving force behind the lease transfer.

Other factual errors are contained in the letter. One states that the SJEDD spent more than $7 million to “actually obtain and condition the property.” In 2008, the Federal Aviation Administration leased the park’s land to the SJEDD at no cost. The district then oversaw a $7 million publicly funded infrastructure installation on the grounds.

Contact Jennifer Bogdan