After dismissing Harry, Madam Bones, armed with a camera, a vial of Dreamless Sleep Potion, a vial of Veritasiurium in her right hand pocket, and her wand in her left hand pocket, apparated to Number Four Privet Drive.
Madam Bones captiously knocked on the door and stood a few steps back while cautiously waiting for an answer.
"Who are you?" asked Petunia Dursley as she opened the door with her husband Vernon behind her.
"I am Amelia Bones, " explained Madam Bones, "I am Head of the Department of Magical Law Enforcement."
"Got lost, " said Petunia stiffly, "Your kind aren't welcome here."
"Yeah, "agreed Vernon firmly, "We don't want any more freaks in this house."
Madam Bones withdrew her wand from her left hand pocket and pointed it at Vernon.
"Stupefy!" cried Madam Bones and Vernon Dursley fell to the floor.
Madam Bones then pointed her wand at Petunia and cried "Stupefy!" and Petunia too fell to the floor.
With Vernon and Petunia both stunned and Dudley at school, Madam had an opportunity to investigate the place.
Madam Bones made a few movements with her wand and said a few nonverbal spells, then looked around the house to see which areas had lit up the mos.
To her dismay, the cupboard under the stairs was by far the most lit.
Opening the door, Madam Bones saw an old cot and pillow with no sheets or case but multiple blood stains. In the very back of the cupboard was a small piece of white paper with small black pen writing on it that read "Harry's room."
Madam Bones took a few pictures of what she saw there and then went up to the bedroom Harry had been using the last few years.
She didn't find anything egregious there, so she went back to where Vernon and Petunia lie stunned and forced a few drops of Veritasiurium down their throats.
After waking them, she questioned them.
"Are you Vernon and Petunia Dursley?" asked Madam Bones.
"Yes, " chorused Vernon and Petunia.
"Has, your nephew, Harry Potter, ever lived in this house?" Madam Bones questioned Petunia.
"Yes, " answered Petunia simply.
"Were you getting paid to care for Harry?" Madam Bones grilled the Dursleys.
"One hundred galleons per month, intended to be used for Harry's food, clothes. and medical stuff." admitted Petunia.
"Did you actually spend that money on Harry?" inquired Madam Bones.
"No, the freak didn't deserve it, " replied Vernon angrily.
"How did that money get spent then?" asked Madam Bones.
"Some extra nice birthday and Christmas presents for Dudley and some nice vacations for Petunia, Dudley, and me, " smiled Vernon.
"Did you ever hit Harry with your frying pans?" Madam Bones questioned Petunia.
"Yes, " said Petunia stiffly, "We expect the boy's cooking to come out right and if it doesn't, then he deserves to be punished."
"Damn straight, " agreed Vernon.
"And you, " Madam Bones rounded on Vernon, "Did you ever smack Harry with your belt?"
"Yes, " said Vernon proudly, "Marge is right, we should not have this nonsense about not hitting people who deserve it."
"Where did Harry sleep while he lived here?" grilled Madam Bones.
"Most of his life, in the cupboard under the stairs," grinned Vernon, though his grin faded when he said, "We moved Harry into Dudley's second bedroom to test whether we were spied on after the freak got a letter from that disgusting school with a very specific address."
"Do you buy Harry new clothes?" Madam Bones inquired.
"No, he doesn't deserve them. He can make do with Dudley's hand me downs, " said Petunia indifferently while carelessly adding, "We don't get him new glasses either. Again, he doesn't deserve them. He can make do with us taping the old ones."
"Do you know if Dudley has ever hit Harry?" Madam Bones asked Vernon and Petunia.
"He has, " admitted Vernon, "And that's okay. If Dudley wants to use the freak as a punching bag, fine by me."
"And finally, have you ever used withholding of meals as a punishment?" Madam Bones questioned Vernon and Petunia.
"Absolutely, " said Vernon fiercely, "Freaks need to be dealt harshly sometimes."
Madam Bones now stunned Vernon and Petunia again, fed them the antidote to Veritasiurium, conjured a pair of handcuffs, used the handcuffs to restrain Vernon and Petunia, and woke them up.
"Vernon and Petunia Dursley you are hereby under arrest. You are guilty of child abuse, child neglect, child endangerment, and theft. By law, since you did not spend the money for Harry's care that was explicitly allocated for that purpose on Harry, you are legally required to repay Harry all of the money you received for his care as restitution. I will be stopping by Gringotts after I leave here and seeing to it that that money is returned to the Potter family vault. You have forfeited custody of Harry, who is now the ward of his godfather, Sirius Black. In addition to theft, you are also guilty of multiple counts of child abuse, child neglect, and child endangerment. You will be transferred to Ministry holding cells while your fate is determined. Owing to the length, frequency, and severity of your crimes, I am going to recommend thirty years in Azkaban."
A nanosecond later, Madam Bones grabbed Vernon and Petunia and apparated to the Ministry and put Vernon and Petunia in separate holding cells that had been bewitched with strong Anti-Escape Spells that Vernon and Petunia would have no chance of overcoming.