The Anatomy Act was passed in 1832, permitting the use for dissection and teaching material of all corpses of paupers who died in the workhouse or a hospital and whose bodies went unclaimed by any relatives or friends. This system was abused from time to time, and corpses were commandeered despite kin or friends coming forward to claim a deceased individual for private burial.
I found this heart-breaking letter in the National Archives, though tantalisingly, we don’t know the end of the story.

William Gellard wrote to the Home Secretary on 28 November 1839 informing him of what happened when his wife went into the Queen Adelaide Hospital in Soho to give birth:

“My Lord, I am induced to trespass upon your Lordship, trusting your Lordship will cause an inquiry to be made into the following circumstances, as I fear the provision of the Anatomy Act has not been complied with.

“My wife was confined at the Queen Adelaide Hospital, Queen Street, Golden Square, on the 12th September 1839. On the 4th October the child died and on the 5th the mother (my wife) died and on the undertaker applying for the child was informed that it was interred. I not being satisfied made further enquiry. The Secretary then gave me the note (enclosed) informing me that the child was at the Anatomy School in Windmill Street [pictured above]. I trust your Lordship will see sufficient reason to cause an inquiry to be made into the circumstances.

“I have the honour to be my Lord your Lordship’s humble servant,
William Gellard, 21 Cecil Court, St Martin’s Lane.”

This note was included in Gellard’s letter; it had been sent to the porter at Windmill Street School of Anatomy by the Secretary of the Hospital, requesting the return of the baby’s body:
“The child you have that was sent to you some time ago is now claimed and I thank you to give it to the bearer.”

The Home Secretary wrote to Gellard informing him that he would be writing to the Windmill Street School, reminding its teachers that the provisions of the Anatomy Act must be complied with and no bodies that were claimed for burial by kin or friends should ever be dissected as teaching material.