However, George Staple, director of the SFO, and four of his senior investigators escaped the threat of jail as they were cleared of any contempt of court by Lord Justice Staughton and Mr Justice Scott Baker.
The High Court Tipstaff, whose job it is to arrest civil offenders, had waited in the court for the judgment. The case was brought by Jeffrey Green, head of Kay Accounting, an accountancy firm raided by the SFO in December.
While the court cleared the SFO of contempt, Edwin Glasgow QC, for the SFO, admitted that the search warrant used to remove the computers from Kay Accounting was "too widely drawn" and should be quashed. Any documents taken from the premises in Radlett, Hertfordshire, and copies taken from the computers will be returned to Mr Green.
Alun Jones QC, acting for Mr Green, said the quashing of the warrant was on the basis that it was unlawful and his client would comply with any future lawful court order to produce documents.
In the judgment Lord Justice Staughton concluded: "There was in our judgment no application aimed at Mr George Staple in his capacity of director of the Serious Fraud Office and therefore responsible for all that it does or omits to do.
"If there had been, we would not have considered that any breaches of the orders were such as to justify proceedings for contempt of court."
Mr Staple said after the hearing it had gone as he expected and he was not prepared to comment further.
In a statement the SFO said: "Members of the SFO carry out their duties in a proper and professional manner. Those involved in today's hearing are looking forward to getting back to work on the Sumitomo investigation."
Andrew Jackson and Christopher Walker, SFO lawyers, Anne Dilks, accountant, and Michael Hainey, computer expert, were other SFO officials named in the action.