Given the input sentence, please extract the subject and object containing a certain relation in the sentence according to the following relation types, in the format of "relation1: word1, word2; relation2: word3, word4". Relations include: product/material produced; manufacturer; distributed by; industry; position held; original broadcaster; owned by; founded by; distribution format; headquarters location; stock exchange; currency; parent organization; chief executive officer; director/manager; owner of; operator; member of; employer; chairperson; platform; subsidiary; legal form; publisher; developer; brand; business division; location of formation; creator.

As analysts including Mr Mott and Mr Martin probed Westpac chief executive Brian Hartzer on Monday at the briefing over the accounting treatment, Mr Hartzer assured them there is nothing tricky about the policy.

Answer: employer: Brian Hartzer, Westpac