A Sydney court has heard the foreign affairs minister in 1975 was pressured not to tell the families of the Balibo five that the men had been killed on the grounds of national security.

Geoff Briot was the foreign affairs minister's chief of staff when five Australian journalists were killed at Balibo in East Timor 32 years ago.

He has told the Glebe Coroners Court, when minister Donald Willesee learnt of the deaths shortly after they happened he was horrified because five of his children were in journalism.

He said the minister wanted to tell the Balibo five's families about the deaths, but was heavily leant on not to say anything on the grounds that it may affect national security. The court heard the minister was very unhappy about it.

Mr Briot said the minister was talked out of it, either by joint intelligence organisation head Gordon Jockell, defence department head Sir Arthur Tange or both men.