Aus: volatile petrol prices and a strange offence.

It's news to us but, apparently, pump prices for petrol fluctuate day by day in Australia. Apparently, Tuesday is the cheapest day to fill up.

But now New South Wales consumer authority inspectors are investigating reports that some petrol stations refuse to sell premium (which means basic) petrol on Tuesdays - forcing customers to buy more expensive - and higher margin - fuels or wait until the price rises.

If the State finds evidence that fuel companies are running stocks down on Tuesday or that fuel is delivered but the outlets are lying about stock levels, NSW will pass it onto Federal authorities to prosecute.

Prosecute what? We don't understand. But under Australia's new all-crimes legislation if it's a fraud, then proceeds will be attachable.

Earlier this month, prices in Sydney went up overnight, without warning, by 17%. The Competition and Consumer Commission said this week that if prices are marked up in for the Easter Rush, relative to the Singapore Gate Price ( "SGP" -a fuel price standard) he will at least name and shame the companies concerned as profiteers.

Earlier this year, the SGP fell sharply but petrol prices in Australia remained high. They did fall a little but the government is concerned that there is price fixing and consumer groups are pushing for investigations, prosecution and jail for offenders.

We can see the crime in relation to anti-competitive practices, incidentally.