The brother of a Red Cross worker murdered after confronting a violent mob of rapists in Sri Lanka has said he can finally grieve properly after four killers, including a politician, were jailed.

Khuram Shaikh, 32, was shot and stabbed in the early hours of Christmas Day 2011 after trying to stop a group of armed, drunken men who gang raped a woman.

The aid worker, from Rochdale, who had been working in Gaza fitting prosthetic limbs, was on holiday with his girlfriend in the southern resort of Tangalle when he was killed.

Ruling party member Sampath Vidanapathirana was yesterday jailed for 20 years for the fatal attack, despite claims that his connections to the family of president Mahinda Rajapaksa meant he was above the law.

A long running campaign by Mr Shaikh's family, backed by their MP Simon Danczuk, saw Prime Minister David Cameron and Prince Charles raising the issue with Sri Lankan authorities.

Speaking from Colombo today, his brother Nasser said: "It's all a bit of a shock to be honest. I never really imagined something as clear cut as this. We've taken each day and each step one at a time."

When asked what has kept him going for the past two-and-a-half years, the 42-year-old said: "It's the love for my brother and missing him so dearly. We had a very close bond. If one door closed I would try and open another door.

"He was very passionate about the work that he did. He worked in some very difficult places, he was very special.

"He was a British Asian lad who rose through the ranks, worked hard and went abroad to do the things that other people would think twice about. I wanted to tell that story."

Mr Shaikh's family were warned they may never see convictions for the death of the aid worker, who represented the Red Cross in North Korea and Ethiopia as well as Gaza.

His brother, an IT worker for the NHS, said: "It wasn't just someone, it was many journalists and many people who said 'this is the norm'. I said 'if that was your family member would you accept it? That there was never going to be any justice?'

"I said 'I'm doing this for my brother'. When you're born and bred in a country that has everything in place, where regardless of your status you will be convicted if you are guilty, then this was quite strange.

"I thought 'I will carry on until the day this finishes'."

He added that he can now finally start to grieve for his sibling, who had "a smile on his face all the time", but is not sure whether justice can ever really be served.

"I never really know what justice really means when I have lost my brother. People say they get closure and they can rebuild their lives and move on, but I can never really understand why people say that.

"To me it's closure but it's just the closure of a chapter. It's part of a journey that will carry on in a different way.

"I never really look at justice in such a way. I've lost somebody and that's never going to change. My parents are still going to do everything they would have done having lost him, and I will as well.

"At least I will be able to grieve for him properly, which I haven't been able to do for two-and-a-half years.

"From the very first day that I found out what had happened to my brother, I was on the phone for the next few days trying to bring him back; and six days later I had to fly to Sri Lanka to bring him back."

Vidanapathirana and three other men - Lahiru Kelum, U Sama Deshapriya and Praneeth Chathuranga - were found guilty of the killing and rape and all jailed for 20 years at the High Court in Colombo.

Mr Danczuk said: "We're pleased that the Sri Lankan authorities have delivered the right decision and Khuram's killers are now behind bars facing justice. They were found guilty on every charge, including gang rape, in what was an absolutely appalling case.

"Nearly three years ago now, Khuram's father asked me if I would help to get justice for his son and we've fought very hard to get this result.

"The fact that a prominent politician is now behind bars is extremely significant and many Sri Lankan journalists told me this would not happen. I hope it marks a turning point for Sri Lankan justice and sends out a message that no one is above the law."