Russia's attempt to quell speculation that it is to block off grain exports doesn't go very far.

The country's farm ministry answered escalating concerns that the tap on shipments was about to be turned off by saying that it had "not sent any grain export restrictions proposals to the government".

That doesn't offer much reassurance. Investors who on Tuesday kept wheat prices ahead on markets in Europe and the US - whose exports stand to gain as Russia's falter - look justified in doing so.

Alternative options?

The so-called denial is too specific to provide much comfort for buyers relying on Russian grain. It did not, for instance, rule out restrictions in the future.

Nor did it rule out other strategies for conserving the country's drought-depleted crop for domestic consumer.

Blatant export clampdowns aren't the only way of encouraging merchants to favour Russian buyers.  And, indeed, the Kremlin may be especially unwilling to look protectionist when it is trying to win support for its application to the World Trade Organisation.

But it is not beyond the country which raised food safety objections to chlorinated rinses to ban imports of US chicken to come up with something imaginative to put a squeeze on the grain trade.

Real power

That said, the statement raised doubts about how much of a say the farm ministry will have in any decision anyway. The denial identified "the government" as the real power.

Even in normal times, agriculture also comes under the wing of one of Russia's deputy prime ministers, currently Viktor Zubkov

In the current turmoil, with the worst drought in 130 years, Vladimir Putin, the prime minister, has been taking a keen interest - as indeed he should. A statement from his office would carry far more credibility.

Economic concern

There is no doubt that Russia is taking its predicament seriously. Why otherwise would Andrei Klepach, a deputy economy minister, feel sufficiently well versed to announce on Tuesday that a downgrade to official crop forecasts was on its way.

But for grain buyers to feel confident in Russia's grain trade will require something more heavyweight in terms of "government" guarantees.