New Delhi, March 28: The CBI is set to file a petition in Allahabad High Court, challenging the trial court’s refusal to hand over the custody of Madhumani Tripathi, one of the prime accused in the Madhumita Shukla murder case.

Special judicial magistrate of Lucknow Digvijay Nath had sent Madhumani, the wife of former Uttar Pradesh minister Amarmani Tripathi, to two weeks’ judicial custody after she surrendered before him on Thursday. Nath had refused to entertain a CBI application, seeking her five-day custody for interrogation.

Madhumani, charged with conspiring to kill Madhumita, went missing from November 13 last year after the CBI served a notice asking her to be present for questioning. The CBI suspected that she had fled to Bangkok.

Sources said the CBI, without wasting any time, is expected to file its petition before the Lucknow bench of Allahabad High Court tomorrow as Madhumani’s custodial interrogation is necessary to complete the investigation into her alleged role in the murder.

The sleuths had quizzed her twice in the past but she had refused to divulge anything.

The CBI will be questioning her on the piece of paper the two alleged killers — Santosh Kumar Rai and Prakash Chand Pandey — were carrying on May 9, the day of the murder. Madhumita’s name, her Paper Mill Colony address and telephone numbers were scribbled on it.

Sources said the CBI plans to match the handwriting on the paper with Madhumani’s. The bureau will also question her on revelations that she had paid the murderers and employed two persons to keep an eye on Madhumita’s house and monitor calls from her several mobile phones, the sources added.

The investigating agency had earlier filed a chargesheet after rounding up five accused. A supplementary chargesheet will be filed, focusing exclusively on Madhumani’s alleged involvement, after the CBI is through with her questioning, sources said.

The agency will write a letter to Interpol to cancel the wanted notice issued against Madhumani at their behest on suspicions that she was hiding in Bangkok, sources said.