WASHINGTON — * Two disclosures related to BCCI's efforts to buy influence have surfaced in the past two weeks:* Documents released by the Senate Foreign Relations Subcommittee on Terrorism, Narcotics, and Foreign Operations show that in November 1986, BCCI put Brazil's most senior diplomat on a monthly payroll to help the bank secure a presence in Brazil. Sergio da Costa, whose last post was as Brazilian ambassador to the US, left the foreign service in 1986. An internal BCCI communique stresses the following as Ambassador da Costa's selling points: his ties to the Brazilian president and his work for Kissinger Associates. Kissinger partner Alan Stoga confirms that da Costa has been "a consultant on Brazilian affairs," to the firm. * Weeks after Edward Rogers resigned as aide to White House Chief of Staff John Sununu last August, he went to work for a BCCI operative. Mr. Rogers, a lawyer who has never practiced law, was hired to represent Kamal Adham, past chief of Saudi intelligence and now a target of United States investigations into BCCI crimes. The US Federal Reserve alleged in July that Kamal Adham, a key figure in the 1982 illegal takeover of First American Bankshares Inc., posed as a front for BCCI when the bank illegally bought First American. Allegations of impropriety in trading connections forced Rogers to terminate the contract, which would have reaped him $600,000.