Serial killer Charles Sobhraj, who is serving a life sentence in a Kathmandu jail, brought an electric shock machine inside the prison cell for self-defence, a report submitted by a three-member investigation committee has said.

Nepalese authorities claimed that they had foiled Sobhraj's attempt to escape from prison, possibly to India, after finding out about an email sent by him from his laptop to a friend asking for some specific chemicals to drug the guards.

• Cop involved in Sobhraj's jailbreak bid held

They discovered the mail after seizing the laptop. The authorities also seized a mobile phone and a cordless phone.

The home ministry had formed the inquiry committee last month to investigate reports that Sobhraj, known as 'The Serpent', was being allowed to use a mobile phone inside the jail.

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The committee submitted its report on Wednesday suggesting several measures to improve jail security, a member of the committee said requesting anonymity.

Sobhraj was allowed to bring only the laptop inside, and he brought the wireless telephone and the cellular phone secretly, the member said. Sobhraj brought the battery-operated electric shock machine concealing it as a massage vibrator, he added.

A police official who was held for facilitating the entry of things Sobhraj needed rejected the reports, and claimed that the equipment were brought purely for communication purposes.