By Cornelius Lysaght BBC Sport racing correspondent

The chairman of the British Horseracing Board, Peter Savill, called for a government inquiry into betting exchanges this week.

He is concerned that the new betting medium, where punters can back a horse to win but also to lose, by effectively playing bookmaker, could adversely affect the integrity of racing.

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The latest race to put the exchanges into the news, just two days after his speech, will act as grist to Savill's mill.

Fluctuating betting patterns surrounding horse Intox before he started favourite for a Ludlow race, caused so much concern that the Betfair exchange alerted the Jockey Club which ordered an investigation even before the off.

On Betfair, the horse, who eventually came ninth out of 10 finishers, drifted from 15/8 to 2/5 before shortening again to 4/5.

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At one stage punters playing bookmaker were prepared to lay what should have been a hot favourite at odds of nearly 2/1.

Although the Intox case is far from reliable, it seems as though somebody had some kind of priviledged information about the horse, who was subsequently found to be lame.

We must now await the results of the Jockey Club probe.

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Also found to be lame after a disappointing run at Carlisle in June was Hillside Girl, another big drifter on the exchanges, whose performance is also being investigated.

These exchanges are the most revolutionary phenomenon to hit betting since the opening of betting shops.

The big bookmakers don't like them from commercial reasons, but, far more important, there is an integrity issue here when defeat, as well as success, can result in profit.