The United States Secret Service is investigating how two uninvited guests were able to enter a White House state dinner held for Indian Prime Minister Manmohan Singh.

The couple, Tareq and Michaele Salahi, are part of the cast of a reality TV show. They evidently managed to slip past a Secret Service checkpoint. The couple then posted photos of their adventure on the social networking website Facebook. One of the pictures shows them posing with Vice-president Joe Biden.

Gatecrashers Tareq and Michaele Salahi in Facebook photo with US Vicepresident Joe Biden