The alleged poisoning of Russian defector Alexander Litvinenko in London makes the front of many papers.
The Mail on Sunday claims he became ill after having a meeting with an associate at a restaurant in Piccadilly.
The Sunday Times says he had three times the maximum limit of deadly metal thallium in his body.
This, according to the Sunday Telegraph, was "an audacious attempt" to murder a fierce critic of President Putin.
The Dyfed-Powys chief constable is quoted in the Sunday Times as saying that men who have sex with children aged 13 or over should not be classed as paedophiles.
Terry Grange, spokesman on child protection, also believes the term "child pornography" should apply only to images of children under 13.
The paper says his comments have been described as "disturbing" by the charity Kidscape.
But in an editorial, the paper says the debate is worth having.
The News of the World claims that the man leading the cash for honours inquiry will hand his dossier over to MPs even if no one is charged.
Downing Street is said to be terrified that Assistant Commissioner John Yates has enough evidence to completely discredit the Blair government.
The paper claims the Tories have been cleared of any wrongdoing, to the fury of Downing Street.
The Crown Prosecution Service now doubts anyone will be charged, it adds.
Chancellor Gordon Brown is pictured in a flak jacket in several papers striding from a helicopter in Basra on his surprise visit to Iraq.
The Sunday Mirror, which describes him as the prime minister-in-waiting, says he has vowed his first move on taking over would be to bring troops home.
A top Labour source is quoted as saying "it would be extremely popular".
The Mail on Sunday says critics have accused Mr Brown of military tourism and spending £250,000 on a photocall.