The Crown Prosecution Service has not implemented a "blanket policy" banning the prosecution of cases of assisted suicide, its head has insisted.
The Director of Public Prosecutions Keir Starmer admitted that no prosecutions had been brought for the offence since new CPS guidelines were issued 18 months ago.
But he said after personally overseeing all the "unique" cases since then, none have involved an individual who was "motivated by the prospect of gaining from the victim's death".
Mr Starmer's comments came after campaigners against a change in assisted suicide law claimed prosecutors were interpreting the new guidelines too liberally and risked creating "legalisation by stealth".
Supporters of a change in the law however said the protocol - which was introduced in February last year and put the motives of those assisting suicide at the centre of the decision over whether they should be prosecuted - is not enough.
In an interview with The Times newspaper, Mr Starmer said: "Any inference that the Crown Prosecution Service has implemented a blanket policy of simply not prosecuting for this offence would be wrong.
"Each case is carefully considered on its own facts and merits. Prosecutors must decide the importance of each public interest factor in the circumstances of each case and go on to make an overall assessment.
"Assisting or encouraging suicide remains a criminal offence, and there must always be a thorough investigation into any suspected cases."
Dr Peter Saunders, campaign director of the Care Not Killing alliance, yesterday said there was a "very real danger" that prosecutors would in effect create laws which ran "contrary to the will of Parliament".
"The director of public prosecutions (DPP) has a duty to uphold the will of parliament but with no prosecutions resulting from the last 44 cases he appears to be interpreting his own prosecution guidance very liberally indeed," he said.