The FBI is warning airlines to be on the lookout for potential hackers, after a U.S. government watchdog suggested that new passenger jets where the Wi-Fi and aviation system share the same network are susceptible to hacking.

The report, released last week by the U.S. Government Accountability Office, suggested that because modern aircraft are increasingly connected to the Internet, there are potentially more ways hackers could access the plane's electronic systems.

The report found that some popular passenger planes, including the Boeing 787, Airbus 350 and Airbus 380 all have passenger Wi-Fi that use the same network as the plane's avionics systems.

This means that although it would be difficult, a hacker using the Wi-Fi could potentially access the plane's communications, display and navigation systems, the report warned.

Following the release of the report, a U.S. security expert was banned from a United Airlines flight after he tweeted about the security gaps on the plane he was taking.

Chris Roberts tweeted a joke about being able to fiddle with the plane's control system through the in-flight entertainment system.

Upon landing in Syracuse, he was arrested by police and FBI agents, and his story made headlines across the U.S.

In response to the report, the FBI and the Transportation Security Administration have issued a warning to airlines to watch for potential hackers or any suspicious activity on planes.

The federal agencies said that while the risk of hijacking a plane through the jet's Wi-Fi system is not considered high, they are taking the report seriously and will be investigating its claims.

'Legitimate threat'

Keith Murphy, CEO of the Ottawa-based security firm Defence Intelligence, said the threat is legitimate.

"It's not something that keeps me awake at night," he told CTV's Canada AM. "But it's certainly something we need to take seriously and put measures in place to make sure that these vulnerabilities are closed."

Murphy said that as technology in our lives become increasingly interconnected, they also become more susceptible to software failures and vulnerabilities.

"Anytime you add another layer, another path of attack into a system, there are always going to be more vulnerabilities," he said. "The real problem in this situation is that the Wi-Fi is shared with the network that is used for avionics, and that makes no sense whatsoever from a security perspective."

He said that security experts have been warning airline manufacturers about the problem for years. Unfortunately it often takes an individual going public with their concerns, like Roberts did with his tweet, before industry feels compelled to change.

In fact Roberts, who works in the security industry, spoke with several airplane manufacturers in 2010 about his concerns, but nothing was done.

"Until it's been brought out publicly, there's not a lot of benefit for the airlines or for other manufacturers to do anything about it," Murphy said.

"I'm just as worried about an unruly kid opening the emergency exit on the plane as I am this, but it's certainly possible and has been proven."