Bortolozzo spent the majority of pre-season on trial at White Hart Lane, figuring in a string of friendlies.
The 19-year-old was born in Brazil but holds an Italian passport, and therefore will not require a work permit.
He has previously played for Estrela Do Norte in his homeland and Treviso in Italy.
Meanwhile, Spurs director of football David Pleat has refuted claims the club have had a bid for Stockport defender Rob Clare rejected.
Hatters boss Carlton Palmer had stated he has turned down an offer for the highly-rated stopper.
But Pleat is adamant Spurs have not lodged a bid for Clare, contrary to Palmer's assertion.
"Nothing could be further from the truth," Pleat told the club's official website.
"I originally knocked this one back earlier in the week and was some 200 miles from Colchester when it was claimed that I was there watching them play Stockport."
