Racing in Britain will resume with four meetings tomorrow, following a six-day shutdown because of an outbreak of equine influenza, the British Horseracing Authority has announced.

The sport has been on hold since last Thursday, after three cases of the highly-contagious virus - subsequently rising to six - were identified at the yard of Grand National-winning trainer Donald McCain in Cheshire.

Hopes of a resumption being possible this week appeared to fade late on Sunday night, when it was revealed four positive tests had been discovered at Simon Crisford's stable in Newmarket.

The BHA said in a statement on Monday night: "After consultation with its veterinary committee, and based on the latest tests conducted by the Animal Health Trust, the BHA's chief regulatory officer, Brant Dunshea, tonight confirmed that racing could resume, but only with strict biosecurity controls in place.

"This decision to return racing in a controlled, risk-managed manner was unanimously supported by the industry veterinary committee."

The news means fixtures will take place over jumps on Wednesday at Musselburgh and Plumpton, and on the Flat at Kempton and Southwell.

Major weekend cards are scheduled for Ascot, where the Betfair Ascot Chase is the feature, Haydock, which will host the William Hill Grand National Trial, and Wincanton, where the Betway Kingwell Hurdle is the headline attraction.

The lockdown may have already cost the industry around £5million - according to leading independent expert Professor Tom Cannon.

Professor Cannon runs the Thoroughbred Horseracing Industries MBA course at Liverpool University, and is well placed to attempt to put a figure on the ongoing cost to racing of no action on the track.

"You've got to look at different parts of the industry - and as yet, nothing lost is on the list of the BHA's major events," said Professor Cannon.

"We've lost around 20 meetings so far, so about 120 races. The biggest issue there will be gate receipts.

"Attendances would only be in the low thousands rather than the high thousands you'd get at somewhere like Cheltenham - so I would have thought it wouldn't be much more than £2-3m lost.

"You then have all the other things that are associated with that because there are lots of logistical costs. First off there are all the tests being carried out - they might cost another £500,000.

"Then there's the question of prize money. Most of it will be reallocated, but I would have thought you'd be talking somewhere in the low millions. There's only really been Newbury that has been lost of the bigger meetings.

"I would estimate that the hit so far to racing would be round about £5m."