Newbury racecourse cancelled racing on Saturday 12 February after two horses dropped dead in the parade ring before the first race of the day.

Fenix Two and Marching Song both collapsed and fell to the ground at the western end of the paddock. An investigation has been started following speculation that they may have been electrocuted.

The remaining runners made it down to the start, where they were checked by a vet before the novice hurdle race went ahead. Trainer Nicky Henderson withdrew his runner Kid Cassidy after his horse also behaved oddly in the parade ring.

Newbury stipendiary steward Paul Barton confirmed that a post-mortem will be carried out on the two horses that died.

Newbury chairman Christopher Spence told the BBC: “It’s a nightmare for everybody. We can’t be certain what it is, we all think it’s electric, but we don’t know.”

The decision to abandoned the meeting was made before the second race and all tickets are to be refunded.

Fenix Two was an unraced six-year-old owned by JP McManus, while five-year-old Marching Song had raced eight times including twice over hurdles.

Listen to interview with Stephen Higgins, Newbury racecourse managing director, talking about the incident