The Wall Street Journal reported that Monaco-based oil and gas company Unaoil has asked a court in the U.K. to quash evidence obtained by the U.K.’s Serious Fraud Office (SFO) in raids on the company’s offices in Monaco earlier this year. The raids were conducted by authorities in Monaco in response to a letter of request for legal assistance from the SFO. In court, Unaoil argued that the SFO’s letter of request did not comply with U.K. law because it did not state the grounds for reasonable suspicion authorizing the search with the required level of specificity. In response, the SFO argued that challenges to the legality of the search should have been addressed in the courts of Monaco, not the U.K. A ruling on Unaoil’s request is expected soon.

The SFO announced its criminal investigation of Unaoil in July following media reports accusing the company of bribing foreign government officials to secure oil and gas contracts. Prior Scorecard coverage of the Unaoil investigations can be found here.

The use of letters of request to obtain evidence located abroad has become increasingly common in corruption cases as enforcement authorities, including the SFO and US DOJ, have stated that they intend to pursue cases even when the evidence is located outside the country. As Unaoil’s request to quash the SFO’s searches illustrates, such searches will trigger difficult questions of jurisdiction and governing law.