The Colombian international is currently thought of as one of European football’s top forwards after netting over 40 goals for the Portuguese giants since his 2012 move to the Estadio do Dragao.
Chelsea have been strongly linked with his signature, but with Diego Costa rumoured to now be their top target Spurs could be clear to move for Martinez.
It is understood that Tottenham chief Daniel Levy met with the 27-year-old’s representatives recently to discuss a deal, and talks went well.
On the back of this an £18m end of season offer is expected, which may be accepted as Porto know that they will struggle to keep the South American for much longer.
Even though Tim Sherwood’s role as manager is unclear, Levy is believed to be keen to sanction moves for big name targets.
If a deal for Martinez goes through, it will be the lilywhites’ second high fee paid for a striker in 12 months, with Roberto Soldado having moved to White Hart Lane for close to £25m last summer.