In 1969, Boni was sentenced to six years imprisonment with "productive hard labour" by an Accra High Court presided over by Justice E. K. Wiredu. He was found guilty together with Joseph Kodzo of inappropriate disbursement of funds of the then Industrial Development Corporation. They were both former Volta Regional Commissioners in Kwame Nkrumah's government. His defence was that he was carrying out the orders of Nkrumah but this was not accepted by the presiding judge.