The 26-year-old has made just one appearance for the Gunners in 2018-19, keeping a clean sheet in the 1-0 Europa League win over Qarabag at Emirates Stadium in December.

Martinez, who spent last term with Getafe in LaLiga, will now spend the rest of this season at Madejski Stadium.

"I am delighted we have been able to attract a goalkeeper of Emi's undoubted ability to Reading," manager Jose Gomes told the club's website after Martinez completed his medical on Wednesday. 

"He will provide excellent competition for the goalkeeper's position and adds quality to our group. I look forward to working with him on the training ground for the first time later today."

Martinez joined Arsenal from Independiente in 2010 but has managed only 14 competitive appearances.

Reading are 22nd in the Championship table after 28 matches and two points from safety.