A man with an address at Santry Lodge, Ballymun, Dublin has been sentenced to four years in jail for emailing two hoax bomb threats to Heathrow Airport.

Adam Busby claimed, in the emails, to be from the Scottish National Liberation Army (SNLA). The 61-year-old was convicted 13 years ago for similar offenses when he made threatening phone calls to Scottish media organizations.

During the trial, the court also heard of other threats and acts of terrorism that he is suspected to have made. In the past, he has threatened the water supply in Manchester. He has also sent bottles of vodka to politicians and journalists which were filled with caustic soda.

Busby pleaded not guilty to the offenses at Dublin Circuit Court.

The court was told that the emails sent to Heathrow Airport were sent for the purpose of causing annoyance, inconvenience and anxiety. The mails were sent from the Charleville Mall Public Library, in North Strand, Dublin.

The presiding judge, Desmond Hogan, said that while this was a serious offense, Heathrow Airport classed it at being at the lower end of the scale as they do not believe that the emails poised a credible threat.

Detective Superintendent Diarmuid O’Sullivan told the court that the emails made threats against specific transatlantic flights, giving flight names and numbers. However, both emails were sent while the planes were mid-flight and the security teams decided there was no need to take action.

Busby suffers from multiple sclerosis and is wheelchair-bound. He will serve two of his four-year sentence.