Det Ch Insp David McAlinden, senior investigating officer from Police Scotland’s Counter Terrorism Policing unit, said the force was “aware of the tragic death of a Scottish man in Krakow”.
He added: “Working in conjunction with COPFS (the Crown Office and Procurator Fiscal Service), Police Scotland is supporting the UK counter-terrorism policing network and the Polish authorities.
“The immediate shared priority is to ensure that identification is properly established for the family, so that repatriation can take place as quickly as possible.
“The family has asked for their privacy to be respected. Our thoughts are with them and everyone impacted by this incident.”
Mark Jewell, a close friend of Campbell’s who regularly DJ’d with him, described him as “a quiet, kind and soft-hearted person, who wouldn’t have harmed a fly”.
He added: “It’s just so tragic that he had to be in the wrong place at the wrong time.
“I had been speaking with him when he was headed over to Poland and I messaged him as soon as I heard about the terrible attack, to ask if he was safe – not for one minute expecting that he would have been caught up in it all.
“I was fully expecting a funny message back from him, saying not to worry. I can’t quite get my head round it all.”