Coast Guard officials in New York Tuesday said they now believe that two phone calls, possibly from the same man, falsely reported that a yacht had exploded off Sandy Hook, setting off a massive air search that came to naught Monday.

In a press briefing at its Battery Park headquarters, the Coast Guard announced that it was increasing the award for information about the hoax from $1,000 to $3,000 "for information leading to the arrest and prosecution of anyone responsible."

A statement from Coast Guard urged anyone with information about the incident to call its investigative service at 646-872-5774 or 212-668-7048 and promised anonymity. [Full text of the statement below.]

"In addition to being a federal crime, false distress calls waste taxpayer dollars, put Coast Guard and other first responders at unnecessary risk and can interfere with the Coast Guard's ability to respond to an actual distress at sea," the service said in a statement announcing today's briefing.

Asked last night about the possibility of a hoax, U.S. Coast Guard Chief Warrant Officer Troy Loining told members of the media at Fort Hancock Monday night: “There is some indication that it could be that. Referring to an extensive air and sea search off Sandy Hook, he said, “We didn’t find anything.”

No people had been found, and no debris spotted in the hours following distress call, which came in around 4:20 p.m. Monday afternoon. The search continued until about 10:20 p.m. when it was was suspended, according to Coast Guard spokesperson Thomas McKenzie, who said the incident would be investigated as a possible hoax.

Earlier Monday, emergency squads from several Bayshore communities were summoned to the tip of Sandy Hook after a report of a boat explosion 17 miles offshore. The vessel, called "Blind Date" was said to have 21 people on board. Nine people were reportedly critically injured. 

According to an earlier statement from Coast Guard Petty Officer Erik Swanson, rescuers received a call from a person using a solar powered radio, who said the on-board radio and GPS system had been destroyed. "We have not been able to reach them ever since," said Swanson. "We have very little information on where it came from. We are focusing on this as a real emergency," he said then.

As of 8 p.m. officials at the scene were not responding to media queries about the possibility that the distress signal might have been a prank of some kind. But emergency personnel from along the Bayshore were leaving the scene. Last June, the Coast Guard responded to reports of a sailboat sinking in the vicinity and called it off when nothing was discovered.

Seven medevac helicopters, ten ambulances, and an army of volunteers and onlookers had gathered at Sandy Hook, but several helicopters and ambulances were later released and no victims had been brought in. 

There were reports of at least 21 people on the boat with all are accounted for and on life rafts, according to an earlier statement from McKenzie.

The rescue staging area is at the  entrance to Fort Hancock, at the tip of Sandy Hook. Atlantic Highlands First Aid Squad, Rumson First Aid Squad, Monmouth Beach Emergency Squad, among others, responded.

 The helicopters were expected to transfer victims from there, according to Brennan.

Visitors were being turned away from the entrance of the national park at Sandy Hook.

The boat Blind Date is a 160-foot motor yacht that was custom built in 2009, according a charter boat company called Charter World. 

Nearly a year ago, the U.S. Coast Guard suspended an active search for missing persons and vessels following a distress call about a sunken sailboat off the coast of Sandy Hook. Loining confirmed the June 14, 2011 incident was a hoax.

During last year's search, the New York offices of the Coast Guard reported receiving initial distress call from a reported 33-foot sailboat named Courtney Lynn at about 3:15 a.m.

Passengers reported that the boat was “taking on water,” an initial released statement from the Coast Guard said. The person placing the distress call had told the Coast Guard that passengers had no radio or flares or horns  and had abandoned ship.

Rescue aircraft and boats from the Coast Guard and other local and state agencies were dispatched but no remnants of the boat reported missing were recovered, U.S. Coast Guard Spokeswoman Jetta Disco said on June 14, 2011.

The U.S. Coast Guard and other state and local agencies responded to more than 60 suspected hoax calls in the northern New Jersey, New York City and Hudson River region in 2011, according to a press release issued by the agency Monday night. Making a false distress call is a federal felony with a maximum penalty of five to 10 years in prison, a $250,000 fine and reimbursement to the Coast Guard for the cost of performing the search, the release stated.

* Christina Johnson, Elaine Van Develde, and Alli Mechanic contributed to this story.

Here is the full text of the statement from the U.S. Coast Guard:

NEW YORK – Coast Guard rescue crews have suspended a search for 21 people who reportedly abandoned ship 17 miles east of Sandy Hook, N.J., June 11, 2012.

This case is now being investigated as a possible hoax call. 

Coast Guard Vessel Traffic Service New York received a distress call at approximately 4:20 p.m. from the crew of the yacht Blind Date stating the vessel suffered an explosion, seven people were injured and all 21 people reportedly aboard the yacht had abandoned ship into liferafts.

Making a false distress call is a federal felony with a maximum penalty of five to 10 years in prison, a $250,000 fine and reimbursement to the Coast Guard for the cost of performing the search.  Coast Guard and other state and local agencies responded to more than 60 suspected hoax calls in the northern New Jersey, New York City and Hudson River region in 2011.

In addition to being a federal crime, false distress calls waste tax payer dollars, put Coast Guard and other first responders at unnecessary risk and can interfere with the Coast Guard’s ability to respond to actual distress at sea.

"More than 200 first responders assembled mass casualty receptions areas in Newark, and Coast Guard Station Sandy Hook, N.J., preparing to receive the reported injured passengers,” said Cmdr. Kenneth Pierro, of Coast Guard Sector New York.

The Coast Guard offers a reward of up to $1,000 for information leading to the arrest and prosecution of anyone responsible for making a false distress or hoax call to the U.S. Coast Guard.  Anyone with information regarding false distress calls is encouraged to anonymously contact the U.S. Coast Guard Investigative Service at 646-872-5774 or 212-668-7048.

Today’s Coast Guard search east of Sandy Hook included two Coast Guard boat crews and four Coast Guard helicopter crews, who searched approximately 638 square nautical miles. Response units from New York City Police Department, Fire Department of New York City, New Jersey State Police and Nassau County Police Department also conducted searches in the area.

For more information contact Coast Guard Public Affairs Detachment New York 212-668-7114 or 917-703-0983.