A constable in Tirunelveli gave sleepless nights to local police officials by mimicking Liberation Tigers of Tamil Eelam chief V Prabhakaran over the wireless, threatening to disturb the Dravida Munnetra Kazhagam Youth Wing conference beginning there on December 15.

Shyam Sundar, posted in the Police Control Room in the town, had spoken on the walkie-talkie over the past three days claiming himself to be Prabhakaran and threatened to disturb the conference, saying LTTE had lost respect in Tamil Nadu after the assassination of former prime minister Rajiv Gandhi.

Later, he had also mimicked the voice of Chief Minister M Karunanidhi and said he (Karunanidhi) was in Tirunelveli for the past one week, and no police official could identify him, officials said.

The conference has assumed importance as there is intense speculation that Karunanidhi might declare his son and youth wing leader M K Stalin as his heir apparent during the two-day show.

Officials, however, said Sundar was not mentally sound and had been taking medicines for his condition. But, there was no explanation why such a person was allowed to work in the sensitive control room.

Sundar, who used to entertain his colleagues by speaking in different voices, had been transferred from the Prohibition Wing to the Control Room only recently.

His antics over the wireless sent shock waves among the police officials who spent sleepless nights, beefing up security for the high-profile conference.

Officials said initial inquiry revealed Sundar was responsible for his threats over the wireless. They also said disciplinary action would be taken against him.