Just a call from a cell phone of an unknown person cooked the goose for an innocent West Bengal-based resident Altaf Ansari, who got branded not only as a terrorist of Harkat-ul-Jehadi Islamia but was tainted as a mastermind of UP serial blasts in November last year.

This is the saga of Altaf Ansari alias Raju, who was picked up in a joint operation of UP and West Bengal Police on December 29 last year and released subsequently on January 14 for want of evidence.

Ansari's fault was that his brother-in-law, who was a co-passenger of HuJI militant Mohammed Tariq, used the mobile phone of the terrorist to give his whereabouts to Ansari.

As the security agencies analysing the call details of Tariq, arrested from outside Barabanki railway station on December 21 last year, they stumbled upon this 113-second call made from somewhere between Allahabad and Lucknow railway station.

Tariq was confronted with this call after which he may have misled police forces of two states -- Uttar Pradesh and West Bengal -- and tried to trap an innocent in connection with the serial blasts in UP.

Tariq, who was alleged to be involved in a  criminal conspiracy to plant explosive devices outside court premises in three cities of UP, said the call was made to the kingpin of the serial blasts last year in Lucknow, Varansai and Faizabad which left a dozen people dead and scores of others injured.

After completing their task, the UP police in association with their West Bengal counterparts picked up Ansari from Kolkata and brought him on transit remand to the Uttar Pradesh for questioning.

Ansari was picked up from North Kolkata and senior police officials from both the states were seen on television screens praising each other for the success of a 'smooth operation.'

However, little did they realise that Tariq was misleading the two police forces.

The police forces' faux pas came to light after the central agencies thoroughly double-checked his statement, which was being found to be correct.

Even brother-in-law of Ansari was traced and questioned, who also corroborated the statement of the victim, the sources said, adding he was subsequently given a clean chit.

He was also brought before Tariq posing as a witness against him.

"We carried a Test Identification Parade of Ansari in front of Tariq, who also failed to recognise him though he had claimed that he knew him personally," a senior official attached with the probe said.

Tariq has, meanwhile, approached West Bengal government for action against the erring officials of West Bengal CID department as he claimed that he was 'tortured' very badly by the police forces.