The 1978 batch IAS officer of Maharashtra cadre has been named as an accused in the scam along with 13 others, including former Maharashtra chief minister Ashok Chavan.
During his tenure as BMC commissioner, Phatak had also chaired the high-rise committee of the corporation. He had approved increase in the height of Adarsh building from 97 m to 100.7 m in September 2007.
According to CBI, Phatak had not referred the decision on increasing the height of the building to other committee members and in return for this favour his son Kanishka was made a member of the Adarsh society.
"Phatak was questioned on what basis he had approved the increase in building''s height and the sources of funds through which his son Kanishka purchased a flat in the society," a senior CBI official said.
Phatak had refuted the allegations and claimed that he was not with the municipal corporation when his son was allotted a flat in Adarsh.
"The high-rise committee of the civic body had approved the building''s height at 103 m earlier. Hence, when I gave my approval for 100.7 m, I did not feel the need to refer the matter to the High-rise Committee again," Phatak had said.
CBI has so far questioned other accused including Adarsh society's chief promoter and secretary R C Thakur, retired brigadier M M Wanchoo, Congress leader K L Gidwani and former deputy secretary of urban development department P V Deshmukh.