New Delhi, Apr 29 (Agencies): Underworld don Dawood Ibrahim has been learnt to have suffered a heart attack, and is in critical condition, sources have told CNN-News18.

The news channel reported that the gangster, who is said to be based in Karachi, Pakistan, is admitted to a hospital, even as his lieutenant Chota Shakeel told CNN-News18 over the phone that Ibrahim is fine.

Family sources rubbished the reports saying that Dawood was fit and fine and that all such rumours were nothing but hoaxes. The family source even said that Dawood had called to check on the well being of his wife Mehjabeen's uncle Salim who is currently hospitalised.

Dawood, who has often been reported to have been suffering from various health issues, is one of the world's most wanted men, and is accused of organising the 1993 Mumbai serial blasts.

Ibrahim is on the wanted list of Interpol for cheating, criminal conspiracy and running an organised crime syndicate, and was designated by the US in 2003 as a 'global terrorist'.

Pakistan denies that the gangster lives in that country, even as several media reports in the past have confirmed his presence there -- his house is in Karachi's posh Clifton locality -- possibly under the patronage of the country's intelligence agency, ISI.

The Indian government has maintained bringing Dawood to justice remains one of its top priorities.

Born in Mumbai's Dongri as Dawood Ibrahim Kaskar, he climbed the ladder of Mumbai's underworld in the 80s after finishing off several rivals, including the Pathan gang.

He used to shuffle between India and Dubai during that period before shifting base to Gulf country.

After the 1993 serial blasts, he was said to have shifted permanently to Pakistan.

Dawood reportedly has four children: son Moin and daughters Mahrukh (married to Javed Miandad's son), Mehreen and Maria.