A British student who skipped bail while awaiting trial for rape fled to Syria to join Islamic State, according to secret documents discovered by The Mail on Sunday.

But despite the heightened terror alert in the UK – symbolised by the Met’s new elite squad of ‘Robocop’ firearms officers – Muslim convert Maarg Kahsay, 25, has now returned and is free to roam London’s streets.

As mainland Europe reeled from jihadi massacres in France and Germany, and Metropolitan Police chief Sir Bernard Hogan-Howe warned that a terrorist attack was a matter of ‘when, not if’, Kahsay’s extraordinary case raises serious questions about the authorities’ handling of the Islamist threat.

Kahsay was given bail when he appeared at Blackfriars Crown Court for a preliminary hearing on a rape charge on June 26, 2014.

Muslim convert Maarg Kahsay (pictured), 25, fled to Syria to join ISIS while awaiting trial for rape. He has now returned and is free to roam London’s streets

Four days later he crossed the Turkish border into Syria at the town of Tal Abyad, according to IS files discovered by the MoS.

The town was then under the control of brutal Islamist fanatics who have recruited at least 850 British jihadis in the war-torn region – all of whom are taught to handle guns and explosives as part of their basic training.

This newspaper has obtained a ‘registration form’ in Kahsay’s name that shows he spent up to two months inside IS territory as a fighter.

For some reason he decided to leave and return home. The document was one of several relating to jihadis.

Dr Shiraz Maher, a terrorism expert at King’s College London, said: ‘The sheer size and volume of the documents are too big for them to be forged.

Also, IS have executed a number of people they suspected of leaking these papers, which would suggest the documents are genuine and from IS.’

Pictured, the Met’s new elite squad of ‘Robocop’ firearms officers. Kahsay was given bail when he appeared at Blackfriars Crown Court for a preliminary hearing on a rape charge on June 26, 2014

When Kahsay failed to turn up at a further court hearing on the rape charge in August 2014, a warrant was issued for his arrest.

He was picked up by police when he arrived at St Pancras Station on Eurostar on September 12 that year.

On his Facebook page, Kahsay posted a picture of himself at the Eiffel Tower the day before he returned to London.

He was sentenced to 14 days in jail for skipping bail. When he stood trial for rape in October he was acquitted. Since then he has also been prosecuted for dangerous driving and given a 12-month suspended sentence.

But inexplicably he has never faced charges for terrorism offences, even though joining IS – a proscribed organisation – carries a jail sentence of up to ten years.

Last week, the Metropolitan Police ‘refused to confirm or deny’ if they were aware of Kahsay’s activities in Syria.

The IS registration form is in Arabic with his date of birth and his nom de guerre Abu Salem Al-Britani.

It says he was born a Christian and converted to Islam aged 15. This was confirmed by friends in London last week.

The form states he was from London and lists Eritrea – his parents’ homeland – as one of the countries he has visited.

But the document’s contents raise other questions about Kahsay, who lives in a council flat in Tufnell Park, North London.

It says he left his British passport in Turkey and gave his mobile phone and iPad to his IS commanders at the Department of Borders, which registers all foreign fighters.

He gives three individuals as ‘referees’ for him in Syria, all of whom have their own chequered histories. One is named only as ‘Faisal’.

The MoS understands this is Fasil Towalde, 21, a fellow Eritrean convert to Islam, who also grew up in Camden, near to Kahsay.

Kahsay was registered by his terrorist commanders when he arrived in Syria. The document discovered by the MoS (pictured) shows his nom de guerre, Abu Salem Al-Britani

Towalde, who was known by the nom de guerre Abu Abdullah Al-Habashi, left for Syria in December 2013 – six months before Kahsay – and died in November 2014 fighting in the flashpoint town of Kobane.

Towalde’s name was also found by this newspaper among the cache of IS documents.

Kahsay’s Facebook page reveals he was also friends with brothers Ondogo and Bilal Ahmed, both Eritrean Muslims. Ondogo, 26, was jailed for eight years in 2007 for the gang rape of a 16-year-old girl at a flat in Crouch End, North London.

Allowed out on licence in August 2013, he fled to join IS in Syria. Two months later, both Ondogo and Bilal, 27, who slipped into Syria earlier, died fighting in Homs.

Kahsay is also friends on Facebook with Sakaria Aden, 22, who was convicted last December for being part of a gang who conned pensioners out of £900,000 to fund IS in Syria.

The MoS monitored Kahsay for several weeks in London. He routinely got up around 1pm. On one occasion a white Muslim convert stayed with him and they both attended Friday prayer at the Al-Risalah mosque in nearby Holloway.

Despite repeated attempts to contact him, Kahsay refused to speak to the MoS and ran away when a reporter approached him.

One member of the Eritrean community in London said he had heard from two sources that Kahsay went to Syria when he skipped bail.

Fasil Towalde (pictured), 21, an Eritrean Muslim who grew up in London near to Kahsay, left for Syria in late 2013 and died in November the following year in Kobane

The source, who did not want to be named, said: ‘I heard this rumour around January 2015. But from what I know he went to Syria when he fled his bail. I heard it as it is being spoken about in the Eritrean community.’

Neighbours of Kahsay said a friend who was a previous tenant at his flat was being monitored by Met counter-terrorism officers last summer.

However, other friends of Kahsay said they had never heard of him going to Syria to join IS and said he was a student at a London university.

Labour MP Keith Vaz, chairman of the powerful Home Affairs Committee, said: ‘This is most surprising.

In the current climate I would have hoped that the authorities would have been more carefully monitoring him given his history and activities.