Watford have rejected a bid in excess of £15m from Leicester City for the striker Troy Deeney.

Watford are determined to keep their captain and have told the Premier League champions he is not for sale, it is understood.

Leicester are looking to increase their firepower and the club have held a long-standing interest in Deeney.

Deeney, who signed a five-year contract last summer, is understood to be happy at Vicarage Road with the club dismissing Leicester’s offer last week; Watford value the 27-year-old much higher than the Foxes’ offer.

Leicester also had offers rejected for Deeney two years ago as they prepared for the Premier League after promotion. But the Leicester manager Claudio Ranieri is not trying to replace Jamie Vardy with Deeney: the former Walsall striker is targeted to complement last season’s 24-goal top scorer.

Leicester are waiting on Vardy to decide whether he will join Arsenal, who have activated his release clause. The England striker, currently preparing for Euro 2016, is not expected to make a decision until after the tournament.

It is understood Leicester have made a counter offer to Vardy but have not matched Arsenal’s deal.

Ranieri is looking for an additional goal threat having sold Andrej Kramaric to Hoffenheim, with Shinji Okazaki and Leonardo Ulloa scoring 11 league goals between them last season.

Deeney joined Watford from Walsall in 2010 in a deal that rose to £650,000 after their promotion to the Premier League in 2015. The League One club would be due a significant chunk of the money should Deeney leave after negotiating a sell-on clause when he left the Banks’s Stadium six years ago.

He has scored 90 goals in 243 league games for Watford, including five in his last five games of the 2015-16 campaign, as his team finished 13th.