Germany has confirmed that a Pakistani student has died while being held in custody in Berlin.
The cartoons sparked anger around the Islamic world
Amer Cheema, 28, hanged himself while alone in his prison cell, a spokeswoman for the German Justice Ministry said.
Mr Cheema had been accused of threatening the editor of the Die Welt newspaper after it printed cartoons caricaturing the Prophet Muhammad.
Some MPs in Pakistan have called for a debate on Mr Cheema's death after his family said he was tortured.
The BBC's Ray Furlong, in Berlin, says the torture claims are highly improbable. Torture is illegal in Germany and even the suspicion of torture would create a huge scandal, he says.
The German authorities say Mr Cheema body will be returned to Pakistan for burial after an investigation into his death.
The caricatures of the Prophet Muhammad, first published in a Danish newspaper, caused uproar in the Islamic world as Islam traditionally forbids images of the Prophet.
There were widespread protests in Pakistan which left five people dead.
A number of western media, including Die Welt, chose to republish the cartoons to uphold the principle of freedom of expression.
'Noose from clothes'
A spokeswoman for the German Justice Ministry, Juliane Baer-Henney, said there was no indication that anyone else had been involved in Mr Cheema's death, the Associated Press news agency reports.
"He used his clothing to fashion a noose and hanged himself on the grill over his window."
She gave no reason as to why he might have committed suicide.
His body was found at 0835 on Wednesday morning, German officials say, two and a half hours after he had been woken by guards.
Mr Cheeba was arrested in March.