New Delhi, May 17 (IANS): Three back-to-back visits by businessman Navneet Kalra's brother-in-law to a Gurugram farmhouse raised suspicion leading to the arrest of the Khan Chacha restaurant's owner in connection with a probe into the black marketing of oxygen concentrators in the national capital, officials said.

A senior Delhi Police official related to probe said that the police nabbed Kalra from the farmhoue after they tracked his brother-in-law's activity.

The official said that his brother-in-law had visited the farmhouse thrice in last 10 days.

He also said that the last location of Kalra's mobile phone was found near a resort in Gurugram, the day he went missing after the Delhi Police seized several oxygen concentrators from a Nege & Ju restaurant and bar in central market of Lodhi Colony.

The police said that Kalra during his hiding in Gurugram used the mobile phone of his domestic help to make WhatsApp calls.

On May 6, taking strict action against people indulging in black markeering of oxygen concentrators, the Delhi Police seized 419 concentrators being sold at exorbitant rates online.

A day later, the police during searches at Khan Chacha restaurant in Khan Market seized 96 oxygen concentrators, while nine concentrators were recovered from Town Hall restaurant. Both these restaurants are owned by Kalra and are in posh Lutyen's Delhi area.

A case was registered under several sections of IPC for cheating, criminal conspiracy, disobedience to order duly promulgated by public servant, Essential Commodities Act, and Epidemic Diseases Act, Deputy Commissioner of Police (DCP) South Delhi Atul Kumar Thakur had said.

Thakur had also said that four men, including the manager of the restaurant, were arrested.

On May 10, the Delhi Police issued a look out notice against Kalra and the case was transferred to the Crime Branch of the Delhi Police.

The police had earlier arrested the Matrix Cellular Services CEO Gaurav Khanna and Vice President Gaurav Suri along with three other employees.

According to the police, the black-marketing of Oxygen concentrator also has a connection in London. Gagan Duggal, the owner of Matrix Cellular Company, was running this racket. He used to buy Oxygen concentrators for Rs 20,000 per unit from China and send them to India. Here in India, these concentrators were being sold for Rs 70,000 per unit. The CEO of Duggal's company in India, Gaurav Khanna, was involved in the black-marketing.

A team of the Crime Branch on Monday also reached the Maidan Garhi police station, where Kalra has been kept after his arrest on Sunday night.

The officials said that the after completing the paper works Kalra will be handed over to the Crime Branch officials.