New Delhi, Aug 18 - The government Tuesday deferred foreign investment proposals of two telecom companies - Unitech Wireless (Tamil Nadu) and ByCell Telecommunication - citing security reasons.

ByCell's proposal to start operations in India has been deferred due to security reasons, an official statement said.

ByCell, founded by a group of Russian businessmen, was to hold 74 percent in an Indian telecom company set up in partnership with Hyderabad-based Jayalakshmi Group.

The company had received approval to begin operations in 13 circles, including Assam, Bihar, north-eastern states, Orissa and West Bengal.

However, the government revoked all foreign collaboration approvals given to ByCell after the home ministry withdrew security clearance to the firm, citing concerns regarding the original source of its investment.