Seven years after JK Rowling's fans tore themselves reluctantly away from the end of the last novel in the series, Harry Potter and the Deathly Hallows, the author has provided a fresh insight into life as an adult for Harry's wife, Ginny Weasley.

After having enjoyed a career as a Quidditch player – the sport invented by Rowling for the novels, in which competitors ride broomsticks – Weasley is now married to the series' hero, Harry Potter, and working as a sports journalist for the Daily Prophet. Rowling has written a series of "live" reports by Ginny, from the 2014 Quidditch World Cup in the Patagonian desert, in which she explains why more than 300 crowd members have been injured.

"Not a single Quaffle thrown, not a single Snitch caught, but the 427th Quidditch World Cup is already mired in controversy. Magizoologists have congregated in the desert to contain the mayhem and Healers have attended more than 300 crowd members suffering from shock, broken bones and bites. The Argentinian Council of Magic is reeling from accusations that their decision to stage a mascot-themed opening ceremony was foolish and reckless," Rowling has posted in the first of two new reports on her website Pottermore.com today.

Ginny goes on to explain how the Norwegian and Fijian mascots clashed, with the Fijian team's Dukuwaqa – a shark/man shape-shifter – taking on Norway's gigantic lake serpent. She quotes a statement from the president of the Argentinian Council of Magic, Valentina Vázquez: "While prepared for the arrival of the Fijian Dukuwaqa, we were surprised when the Norwegian delegation announced that they would also require lake-space for a gigantic lake serpent, the Selma. We had assumed that the Norwegians would be accompanied by their usual troop of performing trolls. We are not aware that any study has ever been undertaken into the compatibility of Dukuwaqas and Selmas, so the Council of Magic cannot accept liability for the unfortunate consequences of placing the two in close proximity."

She then wrangles an exclusive comment from "Chief Consulting Magizoologist" Rolf Scamander, who tells her: "The Dukuwaqa lives in a warm ocean, the Selma in an icy freshwater lake. The former is a shape-shifter that can transform from fish to man, the latter is a serpent that devours human flesh and fish. You would need the brains of a Billywig not to foresee an immediate bloodbath if both were crammed tightly together in tepid, brackish water."

Pottermore said that "knowledgeable Harry Potter fans will spot the link to the screenplay for Fantastic Beasts that JK Rowling is currently writing, the protagonist of which is Newt Scamander, Rolf's grandfather".

The two reports – and the result of the first Quidditch World Cup match, Norway versus the Ivory Coast – can be found in a new location on Pottermore.com: the offices of the Daily Prophet.

Younger readers might of course be disappointed when they learn these reports are fictional. There is some reassurance available, however, in the form of the more or less earthbound version of the game already popular among American students. In this country, too, some Oxford University students are playing. But in the US, still the main focus for the sport, the University of Texas earlier this month retained their World Cup in a (presumably) fiercely contested final against Texas State University to win the seventh World Championship 130-70.