The activist took to twitter on Friday where he shared a screen shot of the message obtained after he tried to access the Deputy President’s account.
Mr Mwangi tweeted that Mr Ruto had blocked him before answering his question on the grabbed school playground.
The playground in question is under investigations and the National Lands Commission, and the agency’s chairman Muhamad Swazuri scheduled to visit it on Friday.
Activists have planned to hold a demonstration dubbed #OccupyPlayGround next Monday at the playground aimed at reclaiming the land from the private developer.
The protest is scheduled to kick off at 9am.