Businesses have been warned against the rising threat of cyber blackmailing after two Polish men were arrested by Greater Manchester Police (GMP) this week for threatening to bring down the website of a 'multi-million pound' internet company.

GMP made the arrest on Wednesday evening at a hotel at Heathrow airport and said that the pair had launched a denial of service attack on the Manchester-based company, causing problems for its website.

They allegedly then went on to blackmailing the company into paying them in order to stop from launching subsequent attacks.

Detective Inspector Chris Mossop of GMP told the Financial Times: "This investigation centres on an allegation that the online company was blackmailed. As part of this blackmail attempt, one of the company's websites was made temporarily unavailable by the offenders.

"Denial of service attacks have become increasingly common offences in recent years and can have a devastating effect on the victim's online business or presence.

"This particular case has involved a fast-time investigation by a number of agencies across a number of countries, including the UK, the US and Poland."