The Scotland international, who joined the Rams from Norwich in 2013 following a successful loan spell, has agreed a new three-and-a-half-year deal at Pride Park.
When contacted by Press Association Sport on Saturday evening, Fulham clarified the contractual situation regarding Martin.
"The signing of a new contract with Derby County does not impact on the terms of the loan arrangement agreed by both clubs," a Fulham spokesperson said.
"Chris Martin will be at Fulham for the remainder of the season and the club still has an option to purchase."
The timing of Martin's new contract comes after the 28-year-old had hit the headlines for reportedly refusing to play for his temporary employers in a bid to force a move back to Derby
Farmed out on a season-long loan to Fulham under previous boss Nigel Pearson, Martin endured a slow start to life at Craven Cottage before netting seven goals in 11 matches.
His return to goalscoring form coincided with the re-appointment at Derby of Steve McClaren, who regularly selected Martin as a lone striker, and led to the unrest at Fulham.
Manager Slavisa Jokanovic maintained the player would see out his deal at the London club, saying Fulham was "not a train station..
you can't come in and out when you want".
Martin has responded by scoring two goals in three games since his return to the side, although he saw a last-minute penalty saved in Tuesday night's 1-0 defeat at Reading
But, in an unusual turn of events, Martin has committed his future to Derby and revealed he "never wanted to leave" and "wants to play under McClaren as soon as possible".
Martin's family have remained in Derby, and the player said he was "excited and happy to be signing this new contract" with the Rams
"At the start of this season I was not in the previous manager's plans, which is a decision that I completely understood and respected," the 28-year-old said on the Derby website
"As a result I had the opportunity to move to Fulham on loan, which gave me the chance to play first-team football elsewhere.
"I am thankful that the board only allowed the move on a temporary basis, because I really didn't want to leave Derby and my family is settled in the area too.
"Derby is a fantastic club with so many things going for it and driven desire to reach the Premier League
I am very happy that the club and the manager see me as part of the long-term future.
"I am committed to being as successful as I possibly can be with Derby.
"I enjoyed playing under Steve McClaren in the past and I feel that he got the best out of me, so I look forward to doing so as soon as possible."
McClaren, whose side drew 2-2 with Leicester in the FA Cup fourth round on Friday night, added: "I know how much Chrissie loves Derby and therefore I am really pleased that he has accepted the offer to extend his deal with the club until the summer of 2020.
"I look forward to working with him again once he returns to the club."
Source : PA
Source: PA