The Italian side have affirmed that the Argentine forward has been sold to Tottenham as Spurs break their previous transfer record for the third time in the current summer
The Italian club have also signed Adem Ljajic from Fiorentina to replace the forward.
Goal exclusively revealed on August 14 that Spurs had entered into negotiations for the Argentine forward as a potential replacement for Real Madrid target Gareth Bale, whilst on August 20 Goal ascertained that talks had escalated with Giallorossi officials in London.
The deal has now been confirmed by the Italian capital club after negotiations persisted for two weeks, the final stumbling block to it's completion having been the fee.
Final arrangements see Lamela depart the Serie A giants for the sum of €30 million, with up to an additional €5 million available in the form of performance incentives.
Tottenham technical director Franco Baldini, who brought the 21-year-old to the Stadio Olimpico in the summer of 2011 from River Plate whilst a director at Roma, has now succeeded in breaking Spurs' previous record transfer figure for the third time in the present window after earlier brokering deals for Roberto Soldado and Paulinho.
Lamela, renowned for his dribbling and pace, tallied 15 goals and 5 assists in 33 Serie A appearances last campaign, whilst going as an unused substitute in Roma's season opening 2-0 win against Livorno on Sunday.
The move looks to have set the stage for Bale's protracted transfer to Real Madrid to be pushed through, Spurs having obtained the desired successor to the Welsh star.