Photo By: Greek Coast Guard
EU border officials say Greece did not respond to an offer to send a plane to monitor a migrant boat that later sank with huge loss of life.
At least 82 people are known to have died in the incident last week, but the UN says a further 500 may have drowned.
Greece has faced criticism for not doing more to respond to the disaster.
The BBC also found that the migrant boat hardly moved in the hours before it capsized contradicting the Greek claim it was on a safe, steady course.
