The couple who caused controversy by gatecrashing a US presidential dinner last week actually met President Barack Obama in the receiving line, the White House revealed yesterday.

The latest revelation came as a "deeply concerned and embarrassed" Secret Service admitted its officers failed to check the guest list.

The White House released a photo showing Virginia couple Michaele and Tareq Salahi in the receiving line in the Blue Room with Obama and Indian prime minister Manmohan Singh, in whose honour the dinner was held.

Obama and Michaele Salahi are smiling as she grasps his right hand with both of hers as her husband, Tareq, looks on. Singh is standing to the left of Obama.

The Secret Service said earlier last week that the president was not in danger because the couple, like others at the dinner, had gone through magnetometers ? screening devices to detect weapons.

But in light of their close proximity to the president, no such claim was made yesterday.

The Salahis were not on the guest list and should have been stopped from entering Tuesday's dinner on the White House lawn, said Secret Service director Mark Sullivan.

"As our investigation continues, appropriate measures have been taken to ensure this is not repeated," he said.

Secret Service spokesman Jim Mackin said officers at the checkpoint had a clipboard with names of the invited guests. But the Salahis were allowed to proceed, even though their names were not on it.

The officers should have called either someone on the White House staff or Secret Service staff before allowing them past the checkpoint, Mackin said.

Earlier, he had said the Secret Service may pursue criminal charges against the Salahis.

Sullivan said: "The preliminary findings of our internal investigation have de­termined established protocols were not followed at an initial checkpoint, verifying that two individuals were on the guest list.

"Although these individuals went through magnetometers and other levels of screening, they should have been prohibited from entering the event entirely. That failing is ours," he said.

Sullivan said it was not good enough that his agency screened more than 1.2 million visitors last year to the White House complex and protected more than 10,000 sites for the president, vice-president and others.

"Even with these successes, we need to be right 100% of the time," he said. "While we have protocols in place to address these situations, we must ensure that they are followed each and every time."

Mackin added: "As this moves closer to a criminal investigation there's less that we can say.