Tottenham Hotspur have signed forward Mohammed Kudus from West Ham United on a long-term contract, the North London club said late on Thursday.

BBC Sport looks at why new boss Thomas Frank wanted to add him to his squad – and why the transfer is a rare move for the north London outfit.

Kudus joins Tottenham for what was reported to be a fee “in the region of” £55m, though the details and structure of the fee were not announced at the time of this article’s writing. There is likely to be performance-based escalators in the fee in addition to a base amount of money.