Bloodline by Felix Francis

Mark Shillingford is happy in his life as a race commentator.  Most of all he loves getting to call races in which his sister is one of the jockeys riding a speedy Thoroughbred.  All that comes to an end with the apparent suicide of his twin.

Race fixing, blackmail, affairs, threats, betting, and a behind the scenes look at what goes into producing a seamless racing program for the live television audience.  All things combine for a face paced read that will make you gallop through the chapters.

This is the first novel I have read by Felix Francis and he does a good job of continuing the legacy of his father Dick Francis.