CBS Reopens David Del Rio 'Matlock' Sex Assault Investigation

It appears CBS is taking another look at David Del Rio and his sexual assault allegation leveled against him by his "Matlock" co-star ... because TMZ has learned the studio has reopened its investigation.

TMZ broke the news ... Del Rio was booted from the hit show after the actor had been accused of sexually assaulting actress Leah Lewis on Paramount property back in October.

Now, multiple sources close to David tell TMZ ... the investigation was reopened prior to Thanksgiving ... and more parties have been interviewed, including David himself alongside his high-powered attorney, Shawn Holley.

In the fall, Del Rio was escorted off the Paramount lot and canned the same day the complaint was lodged ... CBS Studios confirmed at the time his character, a lead in the series, would be written off.

Another inside source reiterates to us his character has been written off the series for future episodes and says "Matlock" is back in production after a pre-planned hiatus.

As we reported ... Del Rio vehemently denied the allegation ... and hired Holley. We hear the reopened investigation is ongoing.