Britain's lightweight four, with anglo-Scot James Clarke at stroke, took one step closer to the weekend's medal final at the World Championships in Munich, with a close second place behind Canada in a tight quarter-final race yesterday.

The British crew showed briefly ahead with 500 metres to go, but eventually Canada slipped past them again to cross the line just over a second ahead, with third-placed Netherlands also qualifying for tomorrow's semi-finals.

Meanwhile, three Russian athletes and their crews were disqualified for committing "anti-doping violations". These are generally believed to allegedly involve the discovery of the use of masking agents.

Till now, doping offences have been rare in the sport, but this Russian difficulty comes in the wake of last year's disqualification that eventually saw Russia's women's quadruple sculls crew disqualified and Scotland's Katherine Grainger and her crew promoted from second place to first.