Delhi Police has arrested businessman Navneet Kalra, who is accused of black marketing of Oxygen concentrators. Officials said, he has been arrested from a farmhouse in Gurugram.<br />'' <br />''<span style="color: #222222;">Kalra was missing after over 500 oxygen concentrators were recovered from his restaurants in the national capital. Delhi Police had issued a look out circular against the businessman. Few days before, the Delhi High Court had declined to grant him interim protection from arrest in the case.</span><br />