BLACKBURN Rovers have promised a full investigation after last night's Premiership clash with Sunderland was called off just two hours before kick-off.

Rovers will look into how the undersoil heating system at Ewood Park failed to cope with a sudden drop in temperature, leading to referee Phil Dowd calling the game off at 6pm.

Rovers had been accused of switching the heating system on too late, but managing director Tom Finn today said the heating on the pitch had been on since Christmas Day.

But he also apologised to disgruntled Sunderland fans, most of whom were already at Ewood Park.

"We are desperately sorry for those fans who travelled so far," said Finn.

"We have arrangements for games like this at this time of year that requires a decision to stop them travelling and it's a regret we didn't do that.

"But we didn't expect any problems and when the fans were travelling down the pitch was fine.

"Normally we would expect the heating system to cope with the falling temperatures but it couldn't and that's something we will be looking at further over the next couple of days.

"I've been here nine years and this is the first time we've lost a game, the system has always been effective.

"It was put on after the players trained on Christmas day and staff have been in, tending to it both days since.

"In the morning the pitch was firm in places, but that was no more than you'd expect after the previous night's conditions. It was fine.

"But when daylight went, the conditions deteriorated sharply and there were parts of the pitch that were unplayable so the referee had no choice.

"We will be looking into the circumstances but we can only apologise to the fans who made the journey."

However, Finn confirmed that, while tickets for last night's game are valid for the re-arranged fixture, refunds will also be available to supporters who can't make that.

He added: "We are conscious people will have bought tickets who might have had family staying with them over Christmas, so if they can't make the re-arranged game refunds can be obtained."

Rovers players have inadvertently got an extra three-day break during the congested Christmas programme, but manager Mark Hughes was a disappointed man last night after being denied the chance to go into the top 10 with a win against a side who only have six Premiership points to show for this season.

Hughes will be hoping his team, on a high after two consecutive wins at Middlesbrough, can return to action on New Year's Eve when Rovers go to Wigan for the first time.