Martins is highly rated in the Eredivisie and has already won seven caps for the Holland national team, despite being born in Portugal.
White Hart Lane scouts are said to have watched Martins on a number of occasions this term and a series of glowing reports have persuaded Andre Villas-Boas to make a £5.5million move at the end of the Premier League season.
The versatile 21-year-old can play at either left back or centre half and would provide the competition Villa-Boas desperately seeks for Benoit Assou-Ekotto after his injury hit season and deputy Kyle Naughton’s unconvincing form.
It’s thought the Spurs boss will fund the transfer by allowing loanee Danny Rose to join Sunderland on a permanent deal and will use the money gained from that to pursue a move for Martins when the transfer window reopens.
Leandro Damiao is another name on Villas-Boas’ summer shopping list after his efforts to bring the Internacional striker to North London in January proved unsuccessful.
The Brazilian international still remains Villas-Boas’ primary target but reports indicate he is also monitoring SC Braga forward Eder and will turn his attentions to the 25-year-old should they fail to sign Damiao again.