Racing chiefs may launch an investigation after a number of horses trained by David Evans were successfully backed to lose by an owner in his yard.

A leading betting exchange sounded the alarm after noting suspicious betting patterns on several all-weather races.

The owner is believed to have laid more than 10 consecutive losers for what is understood to be several thousand pounds.

Paul Struthers, the British Horseracing Authority's head of communications, did not deny an investigation was taking place, but said: "I am afraid we cannot comment on individual cases."

Jockey Club Rule 247 forbids trainers, owners and stable staff from laying their own horses to lose on betting exchanges.

Evans, who has tasted Group-race success with The Kiddykid and has saddled nearly 1000 winners under both codes since becoming a trainer in 1988, refused to be drawn on the matter.

He said: "I have no comment to make."

Meanwhile, Conduit, winner of the St Leger and the Breeders' Cup Turf last season, is set to return to action in the Brigadier Gerard Stakes at Sandown next Thursday.

The Sir Michael Stoute-trained four-year-old is reported to have worked well on the gallops at Newmarket yesterday under Ryan Moore ahead of the one-mile-two-furlong Group 3 event.

Stoute told the Racing Post: "We have eight days to go but, all being well, Conduit will run in the Brigadier Gerard Stakes."