Manchester United manager Louis van Gaal has refused to rule out making a bid for Roma midfielder Kevin Strootman.
Juventus are confident Arturo Vidal will not be lured away by Manchester United in the summer transfer window.
The 23-year-old has spent four separate spells with Yeovil, and a stint with the Seagulls' rivals Crystal Palace, but is yet to appear for Spurs in the Barclays Premier League.
Leroy Lita has left the Amex Stadium to return to Swansea and Seagulls assistant Nathan Jones, who worked with Obika at Yeovil, was keen to bring in the Tottenham forward.
Manager Oscar Garcia told Brighton's official website: "Jonathan is someone we have been aware of for some time because Nathan has worked closely with him in the past at Yeovil and Charlton.
"It is known that we tried to bring him earlier in the season, but were not able to due to an injury, so we are pleased to have him here now."