"I think it has been reported we are no longer working together so that is the matter at the moment," the Scot told a news conference at the British Grand Prix on Thursday.
Asked for more information, given that the split comes at a time in the season when contracts are being negotiated and the driver market is entering full swing, Di Resta avoided the question.
Instead, with Lewis Hamilton sitting on the front row with him, Di Resta said he was focused on his racing.
He then talked about the weekend ahead, how much he appreciated the support of a home crowd and advised fans to get out their rain jackets.
Hamilton senior became Di Resta's manager two years ago and played an important role in helping the driver up the ladder to Formula One after he won the DTM (German touring car) championship with Mercedes.
The 26-year-old has been linked to Mercedes as a possible replacement for seven-times champion Michael Schumacher, 43, when the German decides to call time on his comeback.