fair that says a state department team started asking questions about why some u.s. entities were collaborating with the wuhan lab. the doors began to close. one official reportedly warned that he feared it would open up a can of worms. rich edson with the new details that he reported and uncovered today. rich? >> good afternoon. some former state department officials say others in the bureaucracy were stone-walling an investigation to whether the virus leaked from a lab. vanity fair is reporting a memo from thomas denano, a former acting assistant secretary. he's accusing others in this memo, others at state warning his bureau not to pursue an investigation into the origins of covid-19 because it would open a can of worms. other former officials have pointed fingers at former acting undersecretary for arms control, chris ford. >> he seemed disinterested.