The Sunday Mirror had reported that Bradley Wright-Phillips and Nathan Dyer were caught on CCTV stealing three mobile phones, £145 in cash and cigarettes.
Pearson told the Saints' official website: "The matter of the late-night socialising by these players has already been strongly dealt with internally.
"As far as the other allegations are concerned, the club views these seriously but will await full details and will then decide on what action to take."