Iris de Balme’s disappointing performance at Doncaster remains a mystery after tests carried out on the John Smith’s Grand National hope came back negative.

Sean Curran, who trains at Hatford, near Stanford in the Vale, had his 2008 Scottish National winner checked over on Monday after he trailed home last of 11 finishers behind Wogan in the Grimthorpe Chase on Saturday.

“The vet came and gave him a scope and took some blood from him and he doesn’t seem to have found anything,” said Curran on Tuesday.

“That’s not very good. I’d rather they had found something and I could cure it.

“I’ll see how he is in the next few days and make a plan after that. The Grand National would still be a target if I was happy with him.

“I rode him out this morning myself and he seemed in good form. I’ll just take it steady with him for the rest of the week.”

Iris de Balme is a best-priced 50-1 chance for the National on Saturday, April 10 with Sky Bet.