Should the AFP investigate Abbott

Slippery Pete is now being investigated for defrauding the Commonwealth of $900 in cab charges in 2010.
Should Tony Abbott be investigated for possibly defrauding the Commonwealth of at least $6651 in 2009 whilst advertising his book Battlelines.
From The Independent.

Quote:

Tony Abbott released Battlelines in 2009. It was a book designed to set the tone for his leadership and outline his vision for Australia. From his Sydney seat of Warringah, Abbott flew to Canberra to discuss the book at the National Press Club on 28 July. While it can probably be argued that the Press Club visit was legitimate business – even if it was to discuss and sign copies of his book – how would he explain his trip to Melbourne on 3 August for a dinner event at a Dymocks bookstore? Abbott returned to Melbourne as well as visiting Brisbane and Perth to promote his book. In all, he charged $5,689.36 to the Commonwealth for business that seems personal not parliamentary. That was only the air fares. Including drivers to and from his book events, the taxpayer has put $6,651.96 towards the promotion of his book.

Any comments on this. Do you all feel it is necessary to investigate Abbott?