Media playback is unsupported on your device Media caption The BBC's Sian Lloyd looks at the background to Daniel's case

A mother and her partner have been found guilty of murdering her four-year-old son, who had been beaten and starved.

Daniel Pelka died from a head injury in Coventry in March 2012.

During a nine-week trial at Birmingham Crown Court the boy's emaciated body was likened by a doctor to that of a concentration camp victim.

Mother Magdelena Luczak, 27, and her partner, Mariusz Krezolek, 34, had denied murder.

Both defendants gave a different version of events about what happened and blamed each other.

'Wretched existence'

The court heard Daniel's head injury was one of 30 he suffered and he weighed 14.8kg (32.6lb) in January 2011 and 13.8kg (30.4lb) three weeks before his death.

Image caption The court heard Mariusz Krezolek and Magdelena Luczak worked as a pair

Det Insp Chris Hanson, of West Midlands Police, said Daniel's murder was "pre-planned and premeditated".

"He was beaten, he was drowned and he was poisoned with salt - it was an absolutely wretched existence," said Mr Hanson.

"The investigation has had a profound effect on us all.

"The team have fallen in love with this little boy and we have photographs of Daniel all around our office. We will never forget him."

The Crown Prosecution Service (CPS) said starving Daniel had been forced to steal food from fellow pupils and from school dustbins.

Eryk Pelka, Daniel's biological father, said: "It's a great tragedy that such a little angel had to leave this world.

"I hope that those responsible will be punished severely."

'Coma' Google searches

During the trial the court heard how Krezolek and Luczak, who came to the UK from Poland in 2006, hid the horrifying abuse by claiming Daniel had an eating disorder.

Krezolek and Luczak blamed each other for Daniel's death but text messages between the pair had proved they worked as a team.

One text from Krezolek encouraged Luczak to lock Daniel in his box room. Another, from Luczak, said she had nearly drowned him.

The court heard they had carried out Google searches including one for "patient in a coma".

Krezolek, a factory worker, and Luczak were both drinking heavily and taking drugs, including cannabis and amphetamine, at the time of the abuse.

The couple, who never took Daniel to see his GP, had colluded in covering up an earlier act of cruelty in which Daniel's left arm was broken "clean in half" by Krezolek in a fit of temper.

Jurors were also told how Daniel was left to die in his room - described as an unheated "cell" - for around 33 hours after suffering a fatal head injury at his Coventry home on 1 March last year.

Bruises fear

Luczak, who spoke through an interpreter, told the court she did not understand her own behaviour and that her partner had also tried to strangle her as he attacked Daniel in their home.

She said she witnessed two separate assaults on 1 March, two days before an ambulance was called for the boy.

Media playback is unsupported on your device Media caption Lisa Windridge, Crown Prosecution Service: "We're relieved justice has been done for Daniel"

But Krezolek told the court Luczak had prevented him calling an ambulance after Daniel fell because she was concerned social services would notice bruises on him.

Krezolek said Daniel had lost consciousness while his mother was getting him ready for a bath.

In their evidence, the pair admitted going to sleep on both nights Daniel lay dying in his box room and that they had sex after he died.

Daniel's death is the subject of a serious case review by Coventry's Safeguarding Children Board and a report is due to be published in the next six weeks.

Ann Weir, chair of the board, said new information had emerged during the trial.

'Genetic disorder' claims

The review will look at why police and social services did not get involved after staff at Daniel's school - Coventry Little Heath Primary School - noticed bruising on his neck and what appeared to be two black eyes.

The trial heard Luczak played a leading role in convincing teachers and medical professionals that Daniel's dramatic weight loss was due to a rare genetic disorder.

Gill Mulhall, head teacher at Daniel's school, said his death has had a devastating impact on the community and he will be remembered by a memorial bench and garden.

Krezolek, who served jail sentences for driving while disqualified in 2006, 2007 and 2008, denied murder and causing or allowing Daniel's death.

Luczak denied murder but had admitted through her counsel that she was guilty of causing or allowing her son's death.

The pair are due to be sentenced on Friday.