A senior academic reports wry smiles in the maths department at Imperial College London prompted by the fraud inquiry facing entrepreneur Gary Tanaka in the US. Dr Tanaka, whose lawyers have strenuously denied the allegations against him, was awarded both an MSc and a PhD in applied maths by Imperial in 1970. But his major donation to the college in 2000 - £ million - went to a new business school rather than to his old department.