Police are investigating the death of a man in prison.
The death, at Wandsworth Prison in south London, is being treated as "unexplained", Scotland Yard said.
The 51-year-old man died at 7.40pm on Saturday, a spokesman said.
The Prison Service said contrary to rumours, no hostage situation took place.
A spokeswoman said: "HMP Wandsworth prisoner Jegatheeswarn Balasingham, 51, was taken ill at around 7pm on Friday 26 March 2010.
"Staff were in attendance and attempted resuscitation but Mr Balasingham was pronounced dead at 7.36pm. Our sympathies are with the family and friends of Mr Balasingham.
"Police have been informed and are investigating. As with all deaths in custody, there will be an investigation by the Prisons and Probation Ombudsman."
Scotland Yard said in a statement: "Police are investigating the circumstances of the death of a man at Wandsworth Prison on Friday. The man, aged 51, died at about 7.40pm on Friday evening. Next of kin have been informed.
"The death is being treated as unexplained. A post-mortem examination took place this afternoon. The result was inconclusive and results of further tests are awaited."
Balasingham was serving a four-month jail term after being convicted of causing actual bodily harm, sources said.
