Released sickening video urging Britons to travel to Syria in June last year

Khan was 'thrilled' when he got to meet Labour Minister Ed Balls in 2009

Police today said they are investigating reports that a former British schoolboy who joined ISIS in Syria has been blown up in an airstrike.

Reyaad Khan, 21, from Cardiff, has died just six years after he met former shadow chancellor Ed Balls and said wanted to become the first Asian Prime Minister, according to reports on social media.

South Wales Police today confirmed it had seen claims on Twitter that Khan, a straight A pupil, was killed in a drone strike on the ISIS stronghold of Raqqa on the tenth anniversary of 7/7.

Radicalised: Unconfirmed reports claim British ISIS fighter Reyaad Khan (circled, left) from Wales has been killed in an airstrike in Syria just six years after he was 'thrilled' to meet ex- Labour MP Ed Balls (circled, right)

Notorious: ISIS's fanatical supporters including fellow British jihadi convert Raphael Hostey have claimed Khan (pictured) is dead, killed in an airstrike in Syria on 7/7

Jihad: Khan in training to become an ISIS fighter in Syria. On Twitter he posted the picture with the caption: 'Doin a lil training...'

In a statement the force said: ‘South Wales Police cannot confirm or corroborate reports on social media highlighting the injury or death of Reyaad Khan, who has travelled to Syria.’

The Foreign Office told MailOnline it is unable to confirm Khan's death due to the difficulty of getting information out of Syria.

Khan, who went by the nom de guerre Abu Dujana Britani, had previously boasted of being prepared to be a martyr and claimed he was planning 'fireworks', meaning to become a suicide bomber.

Like many British jihadis, Khan was a frequent Twitter user with multiple posts daily, but his last tweet came on July 6 – the day before he was reportedly killed.

It comes after a number of Islamic State supporters claimed he had died on Twitter.

British jihadi convert Raphael Hostey, 22, from Manchester, who is said to lure Britons to become ISIS fighters or jihadi brides in Syria, reported it.

Under the name Abu Qaqa, Hostey tweeted: 'I remember Abu Dujana Britani said he wanted shahada [martyrdom] in Ramadan.'

Meanwhile, Australian ISIS fighter and senior recruiter Neil Prakash, who goes by the name of Abu Khaled al-Cambodi, tweeted: ‘Its confirmed, one of my most beloved bro @dujjyy00 is shaheed In Sha Allah via dronestrike please ask Allah جل جلاله to accept him!’'

Shiraz Maher, fellow at the International Centre for the Study of Radicalisation, King's College, London, tweeted: 'We're confident he's dead but not absolutely categoric. Likely happened about 2 wks days ago'.

Syrian news accounts said ‘international coalition aircraft’ carried out a missile strike on a car outside the Dar Al Shifa Hospital on July 7.

Khan – a former pupil at Cardiff’s Cantonian High School in Cardiff – was described by friends as a studious pupil who loved sports.

From there he went to St David’s Catholic sixth-form college in the city.

He left for Syria in 2013 with medical student Nasser Muthana, 21, who was joined in Syria three months later by his younger brother, Aseel, 18.

Nasser had taken £100 from his father to go on an Islamic seminar in Shrewsbury in November, but instead went to Syria.

At the time of his disappearance, Khan’s family said they were desperate for him to come home.

His mother Rukia, 41, pleaded: 'Please come back before it is too late. You are my only one son.

‘We can't eat and sleep Reyaad. Please come back before it's too late. I love you so much.’

Sick: Reyaad Khan (left) and Nasser Muthana (right) - both from Cardiff - featured in a propaganda video last June in which they urged Britons to travel to Syria

Reyaad Khan's Twitter profile picture, which comes under the name the nom de guerre Abu Dujana, who boasted of being prepared to be a martyr. His account fell silent the day before his alleged death

Islamic State supporters confirm the death of Reyaad Khan - also known as Abu Dujana Britani - on 7/7

Khan’s father Nazim, 46, speaking today from his home in Cardiff, said he had not had any contact from Syria to tell him his son was dead.

He said: ‘I haven't heard anything. I don't have any contact with him [Reyaad].’

Muthana’s father Ahmed said that he hadn’t spoken to his son ‘for months’.

‘I’m sorry, I don’t have any information,’ he added.

Shortly after leaving for Syria, Khan took to Twitter to boast about his role in the ‘execution’ of prisoners in Syria.

He repeatedly uploaded bloodthirsty posts and pictures on social media bragging about the inhumane killings.

In one he posted graphic photographs of the distorted corpses of alleged victims, tweeting: ‘Guys we caught & executed. This is how they looked less than an hr l8er’.

He also laughed about witnessing the ‘longest decapitation ever’ and boasted in another: ‘Executed many prisoners yesterday.’

In June last year he featured in a sickening propaganda video for the Sunni group in which he urged other Britons to travel to the war-torn country.

In August he posted disturbing online messages joking about the beheading of American journalist James Foley.

Khan mocked the horrific murder on Twitter, saying: 'The brother that executed James Foley should be the new Batman.'

Reports of his death come after David Cameron made a keynote speech on the 'poison' of Islamic extremism.

Mr Cameron called on Britain to abandon its 'passive tolerance' of Islamic extremism and enforce its own values.

The PM promised to tackle 'the poisonous Islamist extremist ideology' sucking in young people and turning to terrorism.

Setting out his plan to confront extremism, Mr Cameron issued a challenge to Muslims to take on the intolerant ideas which 'create a climate in which extremists can flourish'.

Khan is believed to have been radicalised through extremist websites in his bedroom in Cardiff.

It was all so different back in 2009 when Khan, then 15, was said to be thrilled to meet former Labour minister Mr Balls. He also said in a Facebook post he wanted to become the country’s first Asian Prime Minister after sitting on a local youth forum.

His mum Mrs Khan recalled of the visit to see Mr Balls: 'My son came home and was excited and said he had met a Labour minister.'

Just a year after the picture was taken, Khan spoke on a film of his wish to rid the world of 'evil' and of the problems of growing up in a deprived inner-city area.

In an interview at the time, he argued the government wasted resources on 'illegal wars' and said more money ought to be spent on young people to help prevent them being led down the 'wrong path'.

Disgusting: In August last year, Khan posted sickening online messages joking about the beheading of American journalist James Foley (left) by ISIS's chief executioner Jihadi John (right)

Teenager: Before leaving for Syria, Khan (circled), who was a straight A pupil, was outspoken politically and dreamed of being Prime Minister

Asked if the world was a good place, he said: 'The world can be a lovely place but you've just got to get rid of the evil. If everyone could choose the good, the evil will go away.'

Confirming his alleged death will be a difficult task for UK authorities unless ISIS prove the claims are true. It is not thought he had been in contact with his family recently and the Foreign Office has no presence in the Islamic State.

Jihadis are also known to deliberately spread disinformation on social media to confuse and distract security services by falsely announcing deaths to allow fighters to sneak back into their own countries undetected.

British jihadist Imran Khawaja who spent six months in Syria faked his death to try to get back into the UK.

Khawaja, from Hounslow, west London, 27, used a social media account to announce that he had become a martyr after his death in battle. He then tried to sneak back into Britain.

His cousin Tahir Bhatti, 44, from Watford, helped Khawaja to return to the UK by driving him from Bulgaria in June last year, but the pair were arrested by police officers waiting for them at Dover.

In a second incident Islamic State fighters claimed on social media that Tarik Jadaoun, 24, was 'martyred' just weeks before he returned to Belgium.

He was shot dead with Redouane Hagaoui, 22, by a commando squad in Verviers, near the German border.

Similarly, the reports of deaths of high profile ISIS figures have been proven false in the past.

Today the Foreign Office said: 'We are unable to verify these reports. The UK has advised for some time against all travel to Syria, where all UK consular services are suspended.