The Serious Fraud Office has charged two businessmen with corruption following a criminal investigation into alleged bribery in the energy industry.

Ziad Akle, who lives in London, and Basil Al Jarah from Hull were charged with conspiracy to make corrupt payments to secure contracts in Iraq.

The charges are the first to result from an investigation into alleged corruption by a Monaco-based oil and gas firm, Unaoil.

The SFO is also seeking the extradition of a third man, Saman Ahsani, from his home in Monaco to face similar allegations. The 43-year-old was Unaoil’s commercial director. He has not been charged with any offence.

The SFO announced it had started the investigation into Unaoil in March last year following the publication of reports by Fairfax Media and the Huffington Post based on hundreds of thousands of leaked internal emails and documents.

The SFO said it was continuing to investigate the allegations surrounding Unaoil. Last year it was given special funding by the Treasury to pursue the investigation.

The SFO described Akle, 42, as Unaoil’s territory manager for Iraq, and Al Jarah, 68, as Unaoil’s Iraq partner.

Al Jarah is charged with two offences of conspiracy to make corrupt payments, contrary to the Criminal Law Act 1977 and the Prevention of Corruption Act 1906. Akle faces one charge of the same offence.

According to the SFO, the charges concern alleged corrupt conduct within Unaoil, between June 2005 and August 2011, and relate to Unaoil’s client, the Dutch firm SBM Offshore.

Unaoil and SBM said they did not wish to comment. Previously Unaoil has denied being involved in bribery, and called the allegations “malicious and damaging”. The firm also said that some of the information that formed the basis of the allegations against it “has been gathered as a result of criminal activity including extortion”.

Akle and Al Jarah are due to appear before Westminster magistrates’ court in London on 7 December.

Last year, Unaoil launched launched legal action against the SFO, alleging that the anti-corruption agency had unlawfully misused its powers. Its lawyers told the high court that investigators working for the SFO unlawfully raided its headquarters in Monaco and seized a large cache of its documents, phones and computer equipment in a “cavalier” fashion.

Unaoil alleged that the raid amounted to an “excessively wide fishing expedition rather than a proper exercise of” its legal powers. Judges ruled against Unaoil.