The Delhi High Court today expressed unhappiness over the delay in the probe into the death of Congress MP Shashi Tharoor's wife Sunanda Pushkar in 2014 and sought to know the status of investigation so far. <br/><br/>A bench of Justices G S Sistani and Chander Shekhar said more than three-and-half years have elapsed and nothing concrete has emerged so far.<br/><br/>The court's remarks came after Additional Solicitor General (ASG) Sanjay Jain submitted that Delhi Police was not treating BJP MP Subramanian Swamy's plea as an adversarial one and the investigation was being conducted with "utmost diligence". <br/><br/>The ASG also said that the investigation was now at the fag end and a final conclusion will be arrived at soon.' <br/><br/>The BJP leader said various reports have suggested that Pushkar's death was unnatural but delay in getting the scientific report was an attempt to sabotage the probe. <br/><br/>Sunanda Pushkar was found dead under mysterious circumstances in a suite of a five-star hotel in south Delhi on the night of January 17, 2014.