London ? “Those who cure you are going to kill you.”

That, a British priest said Wednesday, was the cryptic warning made to him in Jordan by a purported al-Qaida chief months before the failed car bombings in London and Glasgow that have been linked to a group of foreign Muslims working as doctors in Britain.

British authorities have said the attacks bore the hallmarks of an al-Qaida operation, but security officials say investigators are still trying to determine whether there was any direct link between the alleged plotters and an outside mastermind.

Britain lowered the terrorism threat level on Wednesday. Prime Minister Gordon Brown announced that authorities will increase scrutiny of foreigners recruited for their skills, including doctors coming to work for the National Health Service, which employed all eight suspects in the failed plot.

Canon Andrew White, a senior Anglican priest who works in Baghdad, said he met the man privately with a translator and sheik after holding talks with Sunni Muslim tribal and religious leaders April 18 in the Jordanian capital, Amman.

He said religious leaders told him the man was an al-Qaida leader who traveled from Syria to the meeting. The man, an educated Iraqi in his 40s and dressed in Western clothes, warned of attacks, White said.

“He talked of destroying Britain and the United States and then said, ‘Those who cure you are going to kill you,'” he told the Associated Press.

White, who runs Baghdad’s only Anglican parish and has been involved in several hostage negotiations in Iraq, said he did not understand the threat’s significance at the time. He said he passed the general threat along to Britain’s Foreign Office but did not mention the comment that could be interpreted as hinting at the involvement of doctors in a terror plot.

A spokesman for the Foreign Office, who spoke on condition of anonymity in line with government policy, denied White relayed the man’s identify but confirmed he reported his meeting with the alleged al-Qaida leader.