A third uninvited guest attended the state dinner at the Whitehouse which was gatecrashed by would-be reality TV stars Tareq and Michaele Salahi, the United States secret service says.

According to press reports, the third gatecrasher was a party organiser who entered with the Indian delegation. Unlike the Salahis, who even shook hands with President Barack Obama, the man is said to have spent only a short time at the event.

The Salahis, who are to appear before Congress later this month, have since said they believed they were invited. Investigations into the alleged third gatecrasher are underway. The White House has tightened its security. 

President Barack Obama greets Michaele and Tareq Salahi - wikimedia