Ofcom's head of investigations, Paul Mercer, told BBC News that pirate radio was not a victimless crime.
"Ofcom receive complaints from the emergency services. The two services that are most affected are the National Air Traffic services and the London Fire Brigade.
"In both instances, because of the proximity of the frequencies used by those services and the illegal broadcasters, they can suffer some difficulties when trying to use their radio systems to communicate."
However, one pirate radio DJ told the BBC that while pirate stations may have interfered with the emergency services in the past, it was now a rare occurrence.
Steve, who manages the pirate radio station Ice Cold FM, said: "Problems can occur if people use a badly built link box that connects the studio to the transmitter.
"These systems, called Band 1, can put out multiples of their frequency, so a link on 50Mhz could spill out onto 100Mhz and other high band frequencies.
"I would say 90% of pirates don't use Band 1 links any more. We all use microwave links that are completely interference free," he said.
He added: "I'm not saying there aren't exceptions, but we check all our stuff to make sure it's clean and on the band."
Ofcom says that there are other avenues open for legal broadcasting, such as setting up a community radio station.
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The Department for Culture, Media and Sport has provided money for the Community Radio Fund, managed by Ofcom, which so far has awarded £215,900 to 15 applicants.
But Steve from Ice Cold FM said that it was difficult to win a community radio station licence.
"I wanted to go legal. We tried to get a community based licence and even went off air for a while.
"But once we looked into it, they wanted us to show that we had £25,000 in sponsorship to prove that we could establish the business for a length of time, which is far more than we would actually need.
"Even to apply costs money and Ofcom can still say no, so it's just not worth the effort."
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