Campaigners warned of a "disturbing trend" over fatalities from police confrontations today as investigations were launched into a man's death following a Taser shooting.
The 53-year-old, named locally as Philip Hulmes, was hit with electric probes from the police weapon after barricading himself in his house yesterday.
The incident in Bolton came as an inquiry was launched by the police watchdog into the death of Jacob Michael, 25, who was restrained using pepper spray in Widnes, Merseyside.
The Independent Police Complaints Commission is also probing how bodybuilder Dale Burns, 27, died after being Tasered several times at his flat in Cumbria last week.
Campaign group Inquest said there had already been five deaths in circumstances that involved police use of force excluding firearms this year - compared with four throughout 2010.
Helen Shaw, a spokeswoman for the organisation, said: "The shocking reports about three tragic deaths in eight days following the use of force by police highlights Inquest's growing concern about deaths following contact with the police.
"For too long there has been a pattern of cases where inquest juries have found overwhelming evidence of unlawful and excessive use of force or gross neglect yet the police do not seem to have learnt the lessons from these previous deaths.
"Whilst we await the outcome of the inquests and investigations into these recent deaths it is imperative that the police are reminded that they cannot act with impunity."
The IPCC has been called in to investigate Mr Hulmes' death.
Officers from Greater Manchester Police were called to a house in Salford Road, Over Hulton, at around 8.30pm yesterday over reports he had locked himself inside with a knife and was stabbing himself.
When officers arrived they were threatened by the man and a decision was made to "deploy the Taser", police said.
The spokesman added: "Following that, it became quite obvious the man had serious stab wounds to his stomach."
The man was taken to hospital where he died a short time later. A post-mortem examination was being carried out this afternoon.
The force's professional standards department is investigating and the matter has been referred to the IPCC.
Amnesty International also raised concerns over the use of Tasers.
"Amnesty reiterates that these weapons must only be used in extremely limited circumstances and in instances where there is a serious risk of loss of life or very serious injury," a spokesman said.
"Only officers who receive the highest standard of training on how and when to use Tasers should be armed with these weapons and there must be a high level of accountability whenever Tasers are used."