KENNEBUNKPORT, Maine — The U.S. Coast Guard is now looking into the possibility several mayday calls heard over the weekend were part of a hoax.

The calls started coming in around 10:30 Saturday morning and continued sporadically until noon. 

Upon hearing the calls, more than 100 people--coast guard members, local agencies and good samaritans-- took to the water to search for a man and three children. 

The search crews covered 1,500 square nautical miles, from Ogunquit to Cape Elizabeth. 

The Coast Guard tried to trace the radio call but struggled because of a weak signal.

U.S. Coast Guard Public Relations Officer Lt. Matthew Odom says, "We were never able to pinpoint a specific location based on the weak transmission we received."

RELATED: Man who made mayday call never identified himself

While the tone of the distress call raised eyebrows, officials say the tone of voice in a distress call can be misleading for a variety of reasons.

Search and Rescue Mission Coordinator Commander James McLay says, "In my experience, you can often not tell the true gravity of the situation simply by the inflection or the amount of exertion in a voice."  

Since those mayday calls, there have been no missing person reports about a man and three children.

Officials say they are now looking into the possibility the call was a hoax.

Lt. Matthew Odom says, "We are investigating all leads, including the possibility of the report being a hoax. We have released audio of the mayday call and hope the public will come forward with some information."

RELATED: Coast Guard releases audio from mayday call

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RELATED: Man who made mayday call never identified himself

The Coast Guard hopes someone may recognize the voice of the caller and help bring them more information. 

People have been charged with making fake distress calls in Maine before. It's a federal offense. Penalties for such calls range up to 6 years in prison and fines of up to $250,000.

Officials say it's too early to tell how much the more than 22-hour search costed taxpayers.