Britain's Serious Fraud Office is seeking permission to appeal against a London High Court ruling which sharply criticised the halting of a corruption investigation into a Saudi arms deal, it announced on Tuesday.

New Serious Fraud Office (SFO) director Richard Alderman said the judgment raised "principles of general public importance".

He said he would be seeking permission to appeal to the House of Lords, Britain's highest court.

In the April 10 ruling, two judges said the SFO capitulated to threats from the Saudi royal family over arms deals with Europe's biggest defence company, BAE Systems Plc.

"No one, whether within this country or outside, is entitled to interfere with the course of our justice," one of the judges, Lord Justice Moses, told the High Court in London, calling the decision a failure of government.

"The law is powerless to resist the specific and, as it turns out, successful attempt by a foreign government to pervert the course of justice in the United Kingdom," Moses said.

Two anti-arms trade campaigners had said there was "very large scale bribery" of senior Saudi Arabian officials by the arms manufacturer over the state-to-state Al Yamamah deal and said the probe was halted after the threats.

"That threat was intended to prevent the (SFO) director from pursuing the course of investigation he had chosen to adopt. It achieved its purpose," Moses said.

Critics have attacked former Prime Minister Tony Blair for saying it was right to halt the investigation, arguing it would damage Britain's national security.

Arms sales to Saudi Arabia under the Al Yamamah pact dating back to the 1980s represent the biggest export deals in Britain and their cancellation could threaten thousands of jobs.