A judge has ruled that Britain cannot deport a Saudi migrant who has been previously jailed for a host of crimes because he has been “devoting his time to charity”.

Part of a gang jailed for torturing and robbing sex workers, Thomas Girmay was served with a deportation order in 2009 which would have seen the Saudi Arabia-born migrant deported to Eritrea, from whence his family hails.

But despite the London resident having been sentenced to 14 and a half years in UK prisons, he was granted the right to appeal this by Immigration and Asylum Chamber judge Nadine Finch, who said that the 34-year-old no longer poses a “danger” to society because he “was devoting his time to charity work, going to the gym and playing other sports”.

Girmay “had also developed a business plan and was very keen to obtain employment when his immigration status permitted him to do so”, according to the judge, who said he would “suffer persecution” if deported to Eritrea, referencing a “real risk … of having to perform military National Service duties”.

The convicted criminal, who arrived in Britain with his mother and three siblings in 1990, was part of a gang who repeatedly stabbed a Thai, male masseur in the neck before strangling him to death in 2004, and was sentenced to 11 years jail for theft and grievous bodily harm in the case of another robbery of a sex worker.

According to the BBC, the gang preyed on prostitutes “because they were unlikely to go to the police”.

In September 1999, Girmay was sentenced to 42 months jail for crimes including robbery and dealing crack cocaine, after receiving a number of convictions in the previous two years for which he received fines and supervision orders.

In the same year that she and her children entered the UK, the country rejected the asylum application of Girmay’s Ethiopian mother, but several years later the family was granted indefinite leave to remain.