The pair will join the Hammers from Brazilian club Corinthians on a season-long loan but it could become permanent if all parties are happy, though whether West Ham could afford them is unclear, since both carry price tags in excess of 15 million pounds.

Tevez broke the news of the transfer on his official website. "Carlitos Tevez - along with his former Corinthians teammate, Javier Mascherano, has signed - a contract to play with West Ham United of England," read the statement.

On the surface, the move is nothing short of sensational: never before have two world class players yet to reach their prime - both are only 22 - rejected a host of elite clubs in order to join a middling one. While it true that West Ham are on the up with Alan Pardew at the helm and exciting talents such as Anton Ferdinand, Yossi Benayoun and Nigel Reo-Coker in their ranks, it seems likely that the Argentinian duo's decision was, at least in part, influenced by behind-the-scenes interests.

Corinthians have a 10-year "co-management" deal the Media Sports Investments company, in which Roman Abramovich is said to have a significant holding. It has also been reported that MSI owns the contracts of both players and could therefore block moves to, say, clubs likely to rival Chelsea for domestic or European glory. Another reported shareholder in MSI is Kia Joorabchian, the Iran-born, London-based businessman who last year expressed an interest in taking over West Ham.

Whatever the reasons behind the move, it is unquestionably a major coup for Alan Pardew and gives last season's FA Cup runners-up one of the most impressive-looking squads in the Premiership.

With the addition of Tevez, a prolific striker who's capable of being both subtle and barnstorming, Upton Park is now home to one of the most fearsome strikeforces in England. The Argentinian will surely be an automatic first choice, leaving Pardew the luxury of choosing between Dean Ashton - when he returns to fitness - Bobby Zamora, Marlon Harewood, Carlton Cole and Teddy Sheringham.

Their midfield will also be formidable, with Mascherano, who Sir Alex Ferguson reportedly rated as the world's most worthy recipient of the "new Roy Keane" tag, likely to slot in alongside Reo-Coker, Benayoun and Matthew Etherington.

All of a sudden West Ham look an excellent bet to win this season's UEFA Cup - and have been transformed into genuine contenders for a Champions League spot.