Van Hecke started for the Netherlands in a 2-2 draw against Japan on 15 June in Dallas. He had one year remaining on his Brighton contract, which he declined to extend, prompting Brighton to accept Tottenham's bid that includes a significant sell-on clause.
Van Hecke made 131 appearances for Brighton since joining from NAC Breda in 2020. He started 36 of 38 Premier League matches last season as Brighton finished eighth and secured European qualification for only the second time in club history.
The transfer reunites van Hecke with manager Roberto de Zerbi at Spurs. Tottenham has also signed left-back Andy Robertson from Liverpool and centre-back Marcos Senesi from Bournemouth this summer, reinforcing defensive depth.
Van Hecke's exit mid-tournament affects betting valuations for Tottenham's defensive quality this season and Brighton's squad depth entering their first European campaign in two years.