Mumbai, Dec 8 (IANS): A Mumbai court Monday extended till Dec 22 the NIA custody of arrested Thane youth Arif Majeed, accused of being an Islamic State activist.

Majeed, 23, was arrested Nov 28 after he arrived from Iraq via Turkey and was sent to the custody of the National Investigation Agency (NIA) till Dec 8.

The NIA informed Special Judge Y.D. Shinde that it has made sufficient progress in the investigation and needed further custodial interrogation of Majeed.

It said some online data has been recovered, while some more had to be recovered to confront the accused with the data provided by the service providers.

The NIA said the data showed Majeed's involvement in the case along with three other wanted people.

"We have not opposed the NIA custody as they want to verify and cross-check certain things," Majeed's lawyer Abdul Wahab told IANS.

Majeed, hailing from Kalyan town in Thane district, arrived in Mumbai Nov 28 and was subsequently arrested.

Among other things, he was accused of waging war against a country having friendly ties with India.

Majeed went 'missing' in May this year along with three other Thane youth -- Shahim Tanki, Aman Tandel and Fahad Shaikh.

They left India on the pretext of going on a pilgrimage to holy sites in Iraq, but were later reported as 'disappeared'.

Later, their parents and police learnt they had reportedly joined the IS and were engaged in the war in Syria and Iraq.

Majeed's family Aug 26 learnt from Tanki that Arif was reportedly killed in the war following which the family conducted the funeral rites.

A couple of months ago, the family came to know that Arif was actually wounded in the war and managed to escape to Turkey, from where he arrived by a flight to Mumbai and was nabbed by NIA.