An Australian teenager in Syria who faces arrest if he returns home is running life-saving humanitarian supplies to stranded civilians in the city of Aleppo for British charities, aid workers have told Middle East Eye.

The Australian Federal Police on Thursday issued an arrest warrant for 19-year-old Oliver Bridgeman, who has been in northern Syria since last April, and said it suspected he had gone to the country “with the intention of engaging in hostile activities”.

The announcement came days after the Australian government cancelled Bridgeman’s passport.

But Bridgeman, a Muslim convert who has taken the name Yusuf, says he is in Syria to do aid work.

His lawyers have dismissed the case against him as “nonsensical” and say that none of the evidence presented against him by the Australian authorities “rationally supported” their allegation that he went to Syria intending to engage in “politically motivated violence”.

Posting on Facebook on Thursday, Bridgeman wrote: “They cancel my passport and a few days later they issue an arrest warrant. My only crime is helping the children of Syria.”

Following the cancellation of his passport, he wrote: “No matter what the Australian government say or do, they know that I'm here to help humanity and especially the people of Syria.”

Recent video updates posted by the northern Syria-based Live Updates from Syria aid group, which have regularly featured Bridgeman since last August, show him delivering supplies of Celox, a life-saving medical agent used to stop heavy bleeding, to a hospital in rebel-held eastern Aleppo.

Bridgeman also filmed video and posted photos of the damage to the city caused by Russian air strikes.

Majid Freeman, a British aid worker, said Bridgeman made two trips into Aleppo last month to deliver medical and food aid amid fears that an advance by pro-government forces could cut the last supply route into rebel-held areas and leave civilians besieged.

“He has been there saving lives. He has got a lot of people, both Muslim and non-Muslim, who have been following him and supporting him on his [Facebook] page and they have been seeing exactly how he has been spending his time,” Freeman told MEE.

“He went [to Aleppo] to deliver an ambulance and Celox. He went back a week later to deliver 500 food parcels because the road was still open.

“There was a scare that they would be trapped but they managed to get out. They are planning to get much more in but they will have to see what happens with the road.”

Freeman said that Bridgeman was being criminalised for being an aid worker.

"Non-Muslim aid workers are praised, while Muslims are criminalised for risking their lives doing the same work. In the west the atmosphere is being created that we don’t want refugees coming here. So why are we criminalising people who are going there to help them? If they don't receive aid in Syria then people there will see no other option but to head for Europe.”

Live Updates from Syria is an aid operation run by a British couple, Tauqir Sharif and Racquell Hayden-Best, which publicises it work via Facebook and Twitter.

The couple have been based in Syria since 2012, setting up facilities including a camp for widows and orphans and schools, and also coordinating the distribution of aid donations from Muslim charities in the UK.

Sharif said that the aid supplied by charities in the UK was a “lifeline” for the growing numbers of Syrians displaced by the war.

“We have more and more refugees because the war is ever changing. Areas that were once liberated are being lost back to the regime. There are always new refugees, there are always new faces,” he said.

In a statement issued after Bridgeman's passport had been cancelled, Live Updates for Syria contrasted his case with that of another Australian citizen, Matthew Gardiner, who went to Syria to fight with Kurdish forces against the Islamic State (IS) group.

Gardiner was questioned by police on his return before being released without charge.

“It has become evidently clear that the western governments have one rule for Muslims and another for non-Muslims. Is Oliver Bridgeman's only crime the fact that he is a Muslim?” the group said.

A video posted by Live Updates from Syria last August showing Oliver Bridgeman teaching rugby to Syrian children

MEE understands that Bridgeman was planning to return to Australia and did not intend to stay in Syria indefinitely.

But his lawyers in Australia have accused the government of deliberately stranding him in the country.

They say he could face 10 years in prison if he crossed the border from Syria to Turkey without a valid legal document.

“Without government intervention, it is highly likely he would already be home. Mr Bridgeman had already indicated a willingness to cooperate with authorities. In our opinion, this is a political stunt,” Bosscher Lawyers, a Brisbane law firm said in a statement.

Bridgeman entered Syria in April 2015 after telling his parents that he was going to work for a charity on the Indonesian island of Bali.

Last August he denied allegations in the Australian media that he had joined the Nusra Front, al-Qaeda's affiliate in Syria which operates alongside other rebel groups in the area where Bridgeman is based.

Bilal Abdul Kareem, a journalist in rebel-held northern Syria, told MEE that locating Bridgeman in areas where the Nusra Front was present did not indicate any affiliation to the group because the group worked alongside other rebel factions and it was often unclear who was in charge of a particular area.

He also said that Nusra provided security for some of the refugee camps where aid workers operated.

“Some of those camps have thirty, forty or fifty-thousand people so can we say that they are now all suspects? Will we see arrest warrants issued for every aid worker that has gone into those camps?” said Kareem.

In his first video from Aleppo, Bridgeman was shown teaching Syrian children to play rugby, wearing a vest for the Sydney-based Wests Tigers rugby league team.

Other videos show him reporting on the aftermath of a suspected Russian air strike in central Aleppo, distributing winter clothes and food boxes to children and delivering aid to Latakia province.