In the face of allegations of the involvement of Uttar Pradesh Minister Amarmani Tripathi's wife in poetess Madhumita Shukla's murder, police on Sunday decided to go in for DNA test of the foetus after a post-mortem revealed that she was six months pregnant.

Calling for Tripathi's immediate ouster from the Mayawati ministry, the opposition has demanded a high-level inquiry into the murder alleging efforts were on to tamper with the evidence and intimidate witnesses.

The DNA sample would be sent to Hyderabad for testing to ascertain the paternity of the foetus, police sources said.

Stating the charges levelled against him were the result of 'political rivalry', Tripathi alleged Shukla's family members were 'pressurised' by the Samajwadi Party into making a statement against his family.

"I or any member of my family have nothing do with the killing of Madhumita," he insisted.

Supporting the demand for a CBI probe, the minister of state for stamps told reporters in Lucknow that he was prepared to face any inquiry into the matter.

Tripathi evaded a direct reply to a question whether he would submit himself to a DNA test, merely saying he would fully cooperate with the law.

Madhumita was shot dead at her River Bank Colony residence in Lucknow on Thursday last by two assailants.

The case assumed a new dimension after the sister of the deceased Nidhi Shukla alleged the poetess was involved in a relationship with Tripathi.