The Central Bureau of Investigation on Tuesday detained two people, including an IAS officer, for alleged irregularities in granting sanction to the multi-crore Adarsh Housing Society in Mumbai.

The two -- former Maharashtra Principal Secretary, Urban Development, Ramanand Tiwari and IAS officer Jairaj Pathak -- were called on Tuesday morning to the CBI office in Mumbai and questioned extensively by the agency in connection with the scam, official sources said.

Pathak, a former commissioner of the Brihanmumbai Municipal Corporation, was later arrested.

According to the CBI, Pathak, an IAS officer of 1978 batch, had allegedly allowed the height of the building in up-market Colaba to be raised beyond 100 metres without the approval of the high-rise committee of the municipal body.

The agency has alleged that Pathak, against whom it has got sanction for prosecution, received a flat in the Adarsh Society building in the name of his son allegedly as quid pro quo.

Pathak is named as one of the 14 accused in the case.

Former State Information Commissioner Tiwari, who is also an accused in the case, is alleged to have facilitated the transfer of floor space index from the BEST land to Adarsh. A 1972-batch retired IAS officer, Tiwari is one of the alleged members of the society.

Tiwari allegedly issued letters to the MMRDA, misguiding the planning authority on various issues in the development of the plot.