A west London bodybuilder who faked his own death to slip back into the UK after terror training in Syria has a low IQ and is vulnerable to manipulation, a court has heard.

Imran Khawaja, 27, from Southall, had become a "poster boy" for an Isil-linked terror group and appeared in a number of promotional videos including one where he's filmed holding a severed head.

During the first day of a two-day sentencing hearing, Woolwich Crown Court was shown disturbing footage of Khawaja reaching into a bag of severed heads before pulling one out with his bare hand.

The 27-year-old can be heard saying: "Heads, kuffars [non-believers]. Disgusting."

However, a psychological assessment of the defendant concluded that he had restricted cognitive ability, a lack of critical thinking, poor concentration and an IQ that was within the lowest 12% in the country.

As a consequence he was found to be vulnerable to manipulation and radicalisation.

Khawaja travelled to Syria in January 2014 and became a leading figure within Rayat al–Tawheed (RAT), a group linked to the Islamic State of Iraq and the Levant, the court was told.

By the end of May the group had released an image of the defendant, who pleaded guilty to terror charges last month, claiming that he had been killed in battle.

He was, in fact, on his way back to the UK, being driven by his co-defendant and cousin Tahir Bhatti, 45, from Watford.

In text messages read out in court, Khawaja - who was also known as Imz, Iron, Immi, Touchi and Cashew - complained of not having moisturiser and toilet paper while in war-torn Syria.

He had demanded cocoa butter and toiletries as well as "condoms for the war booty" and complained when his friends failed to send it.

The court heard that Khawaja's family repeatedly begged him to come home even cajoling him with images of Nando's food.

He lied and told them he was doing charity work, telling his sister that he cared more for Allah than his family.

His sister replied on many occasions saying that "their parents' hearts were breaking" and that if "he didn't come home she would come and get him".

In messages home, Khawaja put pressure on his friends and family to send him money because "guns, cars cost money" and he wanted a "Rambo gun" and needed "shooters".

When that failed, prosecutor Brian Altman QC told the court that Khawaja decided, in May 2014, to briefly come back to the UK to sort funds out himself.

The court heard an unidentified man, called Isaac, sent messages from Khawaja's phone to friend Asim Ali, saying: "We want people to think he is gone... just let people think he's dead."

Mr Altman told how Khawaja messaged Ali suggesting he go back with him.

Khawaja said: “It’s OK [in Syria]. Long story, but when I return you come with me.”

Mr Altman told the court: "It shows his return to the UK was not to be permanent, but he had intended to return and he was inviting his friend Asim Ali to go with him. It puts in stark relief the reason for the cover story.”

In a letter to the court, Khawaja apologised for his actions and urged other young Britons not to make the same mistakes he had.

In the note to the judge, he said: “I will just like to apologise for the laws I have broke [sic]. I am sincerely sorry. I have let my country, my family and my community down.

"I have nightmares about Syria. I am lucky to be alive. I would hate to see the young men of Britain to make the same mistake I made and say to them ‘do not get attracted by the propaganda’.”

The hearing continues.