Amey claims that investors have been "short-selling" its share. This is a standard City tactic in which investors offload shares in a company in the hope of buying them back at a lower price.
Amey wants the City's watchdog, the Financial Services Authority, to have a look at the trading in its shares. The City, of course, has rejected the claim.
One analyst fumed: "It's pathetic. They are trying to deflect attention from their own shortcomings."
Meanwhile, shares in the riderless horse that is Costain are trading at a paltry 11p, and rumours persist that it may be put up for sale in a couple of months.
The speculation has been prompted by chief executive John Armitt's imminent retirement and chairman Michael Beckett's resignation.
The company responds that Beckett's replacement will be a big name, and that applications for Armitt's post have been high quality.