The versatile attacker had already joined the Nerazzurri from Tigre on a free transfer ahead of the 2013-14 campaign but was immediately parked at Livorno as Inter did not have a free non-EU slot in their squad.
"Ruben Botta is an Inter player after the paperwork relating to his transfer was completed on Wednesday," a statement on the club's official website reads.
"The 23-year-old Argentine has signed from Livorno on a permanent deal that runs until 2018."
Botta came through the ranks of the Boca Juniors youth academy before joining Tigre in 2009, where he made 77 appearances and scored 10 goals.
Botta failed to make an appearance for Livorno during his short spell there due to injury.