Recently, Gilbert Levin, one of the experimenters behind the Viking labeled release experiment, wrote this letter to the editors of Science. He makes this claim of particular interest
Chlorophyll was reported by spectral analysis of the Martian surface and on newly-appearing material on the lander deck [Levin does not say, but he likely means the Pathfinder lander]. Although the respected scientist who made this claim withdrew the published peer-reviewed publication, inducement is suspected.
Some further digging reveals this interview, in which Levin claims
He [Levin] told me [interviewer] of Carol Stoker, who, in 2002 thought she had detected traces of chlorophyll on Mars, strongly suggesting current life. [...] Levin believes that "NASA made her withdraw the paper."
Around the same time, in 2002, The Guardian reported on the discovery of chlorophyll also:
The Nasa team analysed data obtained by the Pathfinder mission to the red planet which suggests there could be chlorophyll
So. If we believe Levin, there is a peer-reviewed, published, and then retracted paper reporting on the discovery of chlorophyll on Mars. It was likely published some time around 2002, and the author list likely included Carol Stoker. I would very much like to find this paper.