Donald Trump surveillance claims congressman 'met source at White House'

A senior US congressman who claimed communications involving Donald Trump's associates were caught up in "incidental" surveillance has said he met his source on the grounds of the White House.

The meeting came a day before US House intelligence committee chairman Devin Nunes disclosed that US spy agencies may have inadvertently carried out surveillance on the US president and his associates during a routine targeting of foreigners' communications, his spokesman said.