Jan Wiborg, an engineer who became a whistleblower, told several people that he experienced break-ins in his house when he exposed manipulated weather data used in the debate on where Norway's largest airport should be located (Knut Lindh: Hvem drepte Jan Wiborg? (Who killed Jan Wiborg?) 2014 page 73. Among those whom he told about these experiences, we find Johan Martens, the neighbour Fritjof Vernum and the friend Sven Erik Hallgren.
When talking to the parliamentary commission led by Eivind Smith, Hallgren said that there was a mark on his entrance door, and that break-in equipment had been used. A window was broken, furniture detrimented and papers were thrown around in the house. Also, his PC was detrimented, and there were marks on it, as if someone had tried to smash it.