"It was my daughter who found it on Facebook, a message from an Algerian co-worker.
"The police came last night and informed us that what was on Facebook was true, that Kenny had been... he was executed."
Asked how he felt the situation had been handled in Algeria, Mr Whiteside said: "It's just the way life is, I'm afraid.
"I don't hold any grudges against the Algerian army or anything because that's the way they work, that's their system and they weren't bothered about the hostages as such, they just wanted to get the camp cleared of all the terrorists. That was their main objective as far as I can see."
Mr Whiteside said his brother was a planning manager and had worked in Algeria for about five years.