'Spiderman','Chinaking'...These are not Hollywood blockbusters. Rather they are two software programmes related to cellular technology that are giving a headache to central security agencies.

These software programmes are believed to help in changing International Mobile Station Equipment Identity (IMEI) of mobile phones manufactured from China.

The IMEI number is a 15-digit unique number of every mobile handset and comes handy for security agencies in the event of cellular technology being used for any terror or criminal activity.

A case in this regard being handled by Madhya Pradesh Police rang alarm bell for the security agencies as they did not find any relevant law to handle those indulging in such crimes of changing the IMEI numbers and had approached the Department of Telecom for advice, official sources said today.

The DoT supported the decision of the MP Police in which it had slapped Sec 65 of Information Technology Act.

"Whoever knowingly or intentionally conceals, destroy, or alter any computer source code used for a computer, computer programme, computer system or computer network, when the computer source code is required to be kept or maintained by law for the time being in force, shall be punishable with imprisonment up to three years, or with fine which may extend up to two lakh rupees, or with both," the Act says.

The government has already asked telecom operators not to register any mobile which has an incomplete IMEI number and even the Commerce and Industries Ministry has imposed a ban on any import of mobile handsets with such a defect.

The Union Home Ministry has asked the DoT to look for ways to block the softwares but the Telecom department expressed its inability to do so as the names kept changing as well as the domain thereby posing problems for the internet service providers to block them.