The lawmaker has launched a stinging attack against his colleagues after his return to the chamber.
The lawmaker representing Kogi West has experienced a tumultous few weeks after clashing with the police force over his criminal cases in court, and ending up in the hospital with spinal cord injuries.
After he returned to the chamber on Wednesday, Melaye made a request to the Senate President Bukola Saraki to assign him a seat on the side occupied by senators of the People's Democratic Party (PDP) because he was feeling uncomfortable sitting with APC senators.
He said, "Mr President, I want to seek your indulgence that you would call on the Seargeant-at-Arm to look for a comfortable seat for me on this side of the divide (pointing at the PDP side) because I'm no longer comfortable sitting here."
Melaye subsequently moved to the PDP side for the rest of plenary on Wednesday, sparking speculation that he might be about to officially defect to the opposition party, with PDP senator, Ben Murray-Bruce, welcoming him to the party on Twitter.
Melaye has fueled the speculations even further as he took to his Instagram account later on Wednesday to insult APC senators and ask that his seat be changed to PDP's side.
Attaching a picture of him speaking on the side of APC senators, he posted, "I see lion, tiger and snakes on this sit (sic). Change my sit (sic) mbok."
Following the speculations, the APC's spokesman, Bolaji Abdullahi, has released a statement noting that the party respects Melaye's right to associate with anyone.