WESTFIELD -Township police have extensively investigated the threatening letters sent to a couple after they purchased a home last June, Mayor Andrew Skibitsky said Tuesday night.

Speaking at a township council meeting and making the first comments on the case by a municipal official, Skibitsky almost pleaded for anybody with information about the mysterious correspondence to call police.

"Our police have conducted an exhaustive investigation into the threatening letters. Our police went the extra measure and left no stone unturned," Skibitsky said.

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However, he said no charges have been filed in the case "pending the introduction of new evidence."

Westfield police have not responded to repeated calls seeking information about the letters.

Earlier this month, the homeowners filed suit, claiming the letters, coming from somebody identifying himself as "The Watcher," prevented them from moving into the house. The couple claims that the prior owners knew of the letter writer and withheld the information to complete the sale. The couple paid $1.3 million for the house.

Skibitsky last night stressed that the couple, who have three children, received the letters nearly a year ago. Skibitsky said the case involved what would be a disorderly persons offense.

The couple closed on the house on June 2, 2014, and three days later received a letter in which the writer stated he had been watching the house for two decades, and his grandfather and father had each watched it. He claimed to know the previous owners and had asked them to "bring him young blood."

According to lawsuit, the couple received at least two more letters, the last one in July 2014. They claim the prior owners received a letter from "The Watcher" less than two weeks before the closing on the house.

The mysterious letters, which as a result of the lawsuit are now gaining wide attention in news reports around the country, are currently under investigation by both police and Union County Prosecutor's Office, but no information is being released about that investigation.

"The Union County Prosecutor's Office is aware of this matter and is continuing to work closely with the Westfield Police Department on what is an ongoing investigation," said Mark Spivey, spokesman for the prosecutor's ofice.

He said no details of the letters or the investigation could be released.

Skibitsky also declined to comment on the police investigation or the lawsuit.

The names of the current and prior owners, and the address of the house are being withheld for safety.

In the lawsuit the couple said they thought they were buying their "dream" house and that they spent thousands on improvements. The couple said they are trying to sell house but details about the letters have scared off potential buyers.

The prosecutor's office advises anybody receiving disturbing letters to quickly call police.