He contributed significantly to the development of the city of Sandefjord. Among other things, he financed the building of the new town hall. He was a major philanthropist, and was honoured with The Royal Norwegian Order of St. Olav in 1950 and 1962, as well as an honorary professorship at the University of Oslo in 1961. After his death, however, there was much controversy surrounding alleged tax fraud and hidden funds in overseas accounts. In 1984, the Norwegian government put forward a tax claim against the Jahre estate. A series of legal proceedings in the 2000s succeeded in returning part of the fortune to Norway from accounts on the Cayman Islands.