Image copyright PA Image caption Mike Ashley was described in court as a "power drinker"

Sports Direct boss Mike Ashley has won a High Court battle with an investment banker over a £15m deal allegedly made in a pub.

Jeffrey Blue told the court Newcastle United's owner reneged on a promise to pay him a multimillion-pound sum if he increased the firm's share price.

The court heard about "drink-fuelled" meetings in pubs, including one where Mr Ashley "vomited into a fireplace".

Mr Ashley's lawyers said he had won a "comprehensive" victory.

The hearing was told that four years ago Mr Ashley met Mr Blue and three other finance specialists at the Horse and Groom in London and "consumed a lot of alcohol".

Mr Ashley said: "I can't remember the details of the conversations that we had in the pub as it was a heavy night of drinking.

"If I did say to Mr Blue that I would pay him £15m if he could increase [Sports Direct's] share price to £8, it would be obvious to everyone, including Mr Blue, that I wasn't being serious."

He said he paid Mr Blue £1m in "other deals" unrelated to the Horse and Groom meeting.

Image copyright PA Image caption Jeffrey Blue described "unorthodox" working practices at Sports Direct

Mr Blue described Mr Ashley as a "serious businessman", but said the work ethic at Derbyshire-based Sports Direct was "like nothing else I have ever seen" with business conducted "in unorthodox ways and in unusual venues".

Analysis: Damian O'Neil, BBC North East

The £14m High Court case between Newcastle United owner Mike Ashley and a banker offered a revealing insight into how business is done in some quarters.

Stories of monster drinking sessions, kebabs and vomiting into a fireplace emerged as financial expert Jeffrey Blue tried to get Ashley to cough up.

He claimed the Sports Direct founder had promised him the money in a deal struck in a pub, but Ashley said the conversation was no more than a joke.

And a judge has now agreed no-one could have thought he was being serious.

The judge said that during the Horse and Groom meeting Mr Ashley promised him £15m, but Sports Direct chairman Keith Hellawell said Mr Blue only mentioned the figure of £1m to him.

Ruling in Mr Ashley's favour, judge Justice Leggatt said: "No reasonable person present... would have thought that the offer to pay Mr Blue £15m was serious and was intended to create a contract.

"They all thought it was a joke. The fact that Mr Blue has since convinced himself that the offer was a serious one, and that a legally binding agreement was made, shows only that the human capacity for wishful thinking knows few bounds."

He ordered that Mr Blue would have to pick up Mr Ashley's legal bill of £1.5m, as well as his own of "one million odd".

In a statement after the ruling Mr Ashley said: "The only reason the Sports Direct share price exceeded £8, and will hopefully do so again, is because of the sterling efforts of all the people who work at Sports Direct."