A British jihadi who helped an Islamist group in Syria record videos of severed heads and then faked his own death in the hope of being able to return home undetected was sentenced to 12 years in jail on Friday. Imran Khawaja, 27, of Southall, west London, travelled to a training camp in Syria in January last year and joined Rayat al Tawheed, which became aligned with Islamic State, prosecutors had said. "Khawaja was seen in a disturbing video posted on social media which includes a bag of severed heads," a police statement said after Friday's sentencing at Woolwich Crown Court. "He appears in the footage with his face covered picking up one of the heads from the bag and showing it to the camera." In May 2014, the group put out a message on social media claiming that he had been killed, alongside an image of two masked men holding a flag associated with Islamic State. "Khawaja ... faked his own death in order to conceal his entry back into the UK," said Commander Richard Walton, head of the SO15 Counter Terrorism Command. But Khawaja and his cousin Tahir Bhatti were arrested last June at the southeastern port of Dover. Passing sentence, Justice Jeremy Baker said Khawaja, a former immigration center worker, was a risk to the public and described him as a "willing and enthusiastic" participant in extremist recruitment films. "You took part in the production of films designed to promote the Islamic State cause and encouraging U.K. Muslims to join you in jihad," he said. "Your interest was sufficiently profound for you to travel to Syria to train for jihad." Khawaja, from London, admitted preparation of terrorist acts, attending a terrorism training camp, receiving weapons training and possessing a firearm for terrorism use. He will serve a minimum of eight years. His cousin, 45-year-old Tahir Bhatti, was sentenced to 21 months after admitting assisting Khawaja. British officials say hundreds of Britons have joined extremists in Syria. Police say the number of arrests for suspected Syria-related terror offenses jumped six-fold last year. "Imran Khawaja's actions are one of the most appalling examples of violent extremism that I have seen committed by British jihadis returning from Syria," said Deborah Walsh, Deputy Head of Counter Terrorism at the Crown Prosecution Service. "Photos and videos of Khawaja posing with child soldiers and severed heads defy the understanding of civilised people and paint a picture of a man who would stop at nothing to spread terror and hatred," she added in a statement. Bhatti, 45, of Watford, north of London, pleaded guilty to helping him and was sentenced to 21 months in jail. Asim Ali, 33, who had admitted providing money to Khawaja, was also sentenced to 21 months.