Sharma, who is a suspect in the case, has been refusing to take a lie-detector test for several months now on grounds of ill health and various other pretexts. The first time he was asked to undergo the lie-detector test, he cited reasons of ill health. Subsequently he expressed inability to do so on the ground of his father's death and later on account of his mother's illness.

According to a senior police officer in Delhi: ``In the beginning of August, he had expressed his inability to take the test as his mother was unwell. Now he says he is suffering from asthma and therefore cannot take the test. However, he has furnished the same medical documents that he had given to us several months ago and this is what made us sit up and takenotice.''

Tired of going round in circles, the Delhi police have decided to constitute a medical board consisting of senior independent doctors to examine him. Sharma has taken the test three times already, but since they were incomplete, the police want to put him through it once again. ``We want to test Sharma again as there were discrepancies between the statements made by him and those made by Shivani's husband,'' said a senior police officer.

Apart from Sharma, Shivani's husband Rakesh Bhatnagar, her sister and brother have been subjected to this test.

Sharma is currently posted as the vigilance chief of Air-India in Mumbai. He has earlier worked with the Central Bureau of Investigation, the Interpol and in the Prime Minister's Office.

Thirty-two-year-old Shivani was found murdered in her Patparganj flat on January 23. She was stabbed by a kitchen knife and strangled by an electric wire. Her two-month-old baby boy was the only witness to the crime.