Guidelines on conflicts of interest in the civil service are 'not 100 per cent loophole-free', Civil Service Secretary Lam Woon-kwong has admitted.
He also expressed grave reservations about checking declared investment records at random, saying privacy and individual rights might be infringed.
But Mr Lam pledged to consider broadening public inspection of records from policy secretary level to department head level and to seek more details about the jobs held by officials' wives.
The present system requires regular declarations from about 2,900 officials, but disclosure by only 26 policy secretary-rank officials.
Lawmakers at a Legco meeting on Commissioner of Inland Revenue Wong Ho-sang's case said the guidelines should be tightened.
Mr Wong is being investigated by the Director of Audit after he apparently failed to disclose his involvement in a taxation company owned by his wife under guidelines revised last year.
Cheung Man-kwong of the Democratic Party demanded the disclosure of the records of all department heads, as well as detailed descriptions of the nature of jobs held by their wives.