West Ham emerge as shock contenders to beat Chelsea and Tottenham to £70m Kalidou Koulibaly transfer from Napoli

He is valued at around £70million by his Italian club and has three-and-a-half years left on his current contract.

David Moyes currently has Fabian Balbuena, Angelo Ogbonna, Issa Diop and Winston Reid as his available centre-halves at the London Stadium but the acquisition of Koulibaly would be a major coup.

However, the report adds that they could well face competition from Manchester City.

The reigning Premier League champions' defensive struggles have been exposed this season after failing to replace Vincent Kompany and losing Aymeric Laporte to injury.

Manchester United were linked with Koulibaly for a few years but were priced out of a move when Napoli demanded in excess of £90m last summer.

It meant the Red Devils opted to sign Harry Maguire instead, paying Leicester £85m for the England star.

However, Chelsea and Tottenham have both been tipped with making moves for Koulibaly in January, who could be allowed to leave Napoli.

Senior players are known to have been upset with the actions of owner Aurelio de Laurentiis which led to him dumping Carlo Ancelotti hours after he had guided the side into the last 16 of the Champions League.

And Koulibaly is thought to have been one of those leading the challenge to the authority of De Laurentiis.

Chelsea have been long-term admirers of Koulibaly but twice seen attempts to sign him blocked.

But Frank Lampard's side could do with an experienced central defender to provide some know-how in the back line, and should Koulibaly become available he would obviously have an interest.

Spurs also desperately need to strengthen at the back with the team conceding far too many soft goals this season.

Jose Mourinho was a huge fan of the Senegalese star during his time in charge of United, and recommended they signed him when he was there.

Hammers boss Moyes is also keen to strengthen his squad elsewhere after the team slipped into the relegation zone over the Christmas period.

He explained: "I think that we want to add a player in that department [midfield].

"In January it'll never be easy for anybody, but if we could, it would help us.

"I think we're also talking with some other goalkeepers as well. I do know that we're looking to add another goalkeeper to the squad.

"At the moment the only people I’m really concentrating on are the team and the players I’ve got here.

"If good players are available, there’s no doubt that the owners and myself will be looking at them."