New Delhi, Dec. 9: Former Delhi cop L.T. Hrangchal today said the signature on the character certificate furnished by the rape-accused Uber cab driver 'appears to be mine' but denied signing the document, which raises the possibility that some police insiders may be 'selling' signatures.

Former Delhi police commissioner Ved Marwah confirmed that such Photoshop-driven corruption indeed happens within the department, which casts doubt on how far a police verification by Uber may have helped.

'I was sent a copy of the character certificate over WhatsApp by friends in Delhi police, and was shocked to see that the signature on it appears to be mine,' Hrangchal told The Telegraph over the phone from Mizoram, where he is now posted.

'It's a very serious matter and very embarrassing for me as I never issued it. Delhi police have said it was a forgery but they need to get to the bottom of it to find out what ails the system.'

Hrangchal backed his former Delhi colleagues' stand that a date mismatch on the certificate clearly indicated forgery, but contradicted their claim that the document had been issued in the wrong format.

'I issued police verification certificates to several people during my Delhi posting,' he said. 'The format of the certificate issued to the accused driver looks familiar to me.'

Marwah called Indian police certificates 'nothing but a sham', accusing the force's lower rungs of corruption as well as slipshod work.

He said that if an applicant was ready to pay, 'cops can help him forge the signature of a senior officer'.

Or, they might scan a genuine certificate signed by the officer, replace the name and other details with the help of a computer and get a fresh printout. Or they might 'cut and paste the signature from some other document', Marwah said.

Further, he said, even genuine police certificates mean little as they are usually issued on the basis of whether the person has been accused of a crime within the jurisdiction of the police station issuing the certificate.

'If he faces criminal cases at some other police station, it goes unnoticed,' Marwah said.

The alleged taxi rape in 2011 from which the accused cabbie was exonerated for lack of evidence hadn't taken place in the area of Ambedkar Nagar police station, whose certificate said he had no criminal record.

Currently, Delhi police are required to check whether an applicant has a criminal history anywhere in the capital - the headquarters have such a database - and contact the police in his home state if he is a migrant.

They do neither, Marwah said. 'Policemen hardly go to the person's residential address to check whether he stayed there, and issue certificates on the basis of documents provided by him.'

Accused cabbie Shiv Kumar Yadav, 32, did not live in Ambedkar Nagar police station's area - as the police have conceded - and seems to have got the certificate on the strength of a fictitious address.

Officers said Yadav's interrogation had revealed the Mathura native faced several criminal cases in his home state.