Fresh criticism over BAE inquiry
Britain's commitment to fighting bribery is to be investigated by a prominent anti-corruption group.
The Organisation for Economic Co-operation and Development's move is prompted by the UK's decision to drop a probe into defence firm BAE Systems.
The Serious Fraud Office said it abandoned the investigation into a huge Saudi arms deal in December because it could threaten national security.
Critics said it demonstrated the UK was lukewarm about tackling corruption.
SFO investigators had been looking into claims that BAE paid bribes to secure the al-Yamamah arms deal in the 1980s, which involved Tornado and Hawk jets and a major airbase construction programme.
The UK defence company denied all claims of corruption related to the deal, thought to have been worth £40bn ($77bn) to the firm.
Media reports alleged that Saudi Arabia had threatened to cancel a further £10bn deal to buy 72 Eurofighters from BAE Systems unless the inquiry was halted.
The OECD said its working group on bribery had "reaffirmed its serious concerns" about the SFO's decision to drop the al-Yamamah inquiry, questioning whether the move was consistent with the OECD's anti-bribery convention.
It said the group welcomed recent increases in resources for investigations, but the continuing lack of any prosecution "may raise broader issues".
The OECD said it would review whether "systemic problems" explained the lack of foreign bribery cases brought to prosecution in the UK. Its inquiry will include an on-site visit, to be conducted within one year.
The head of the SFO, Robert Wardle, told the BBC on Monday that he had come under no political pressure to drop the al-Yamamah inquiry.
Mr Wardle said he had made the decision independently, following warnings that continuing the investigation could damage UK national security.