Will Mars Express find traces of life?

Images from the Mars Orbital Camera on NASA's Mars Global Surveyor appear to show dark spots which appear near the south pole of Mars in early spring ('slice' on left). According to a group of Hungarian scientists these spots may be a sign of life on Mars.

(This composite image shows a Mars Orbital Camera image superimposed on a Hubble image of Mars. It is intended to be illustrative rather than scientifically accurate.)