"It is nonsense to say that Gwenog [Jones] wanted the Holyhead fans to riot. Yes, maybe she did say that Wilda [Griffiths] deserved to be gnawed to death by starving tarantulas, but that was a light-hearted remark."
-- a Holyhead Harpies representative (DP4)
Ministry fears of violence at the match between traditional rivals Holyhead Harpies and Puddlemere United were realised when former Harpy, Chaser Wilda Griffiths, disappeared midway during the match. Many Puddlemere and Holyhead supporters had handed in “dummy” wands at the gates and used their real wands during the ensuing riot. Holyhead team captain Gwenog Jones is said to be “helping the Ministry with its enquiries” (DP4).
In the book Quidditch Through the Ages, there is a footnote to the rules of Quidditch explaining that wizards, including those in the crowd, have had the right to carry a wand since 1692, so long as they don't use them (QA6). The Ministry's attempt to collect or confiscate wands before the Holyhead v Puddlemere match was always likely to have failed. Royston Idlewind could have told them a thing or two about the futility of trying to keep wizards with wands under control (Pm:Quidditch).
If you are "helping the police with their enquiries" (like Gwenog Jones is after the Puddlemere-Harpies match), it usually means you are being held in custody while they gather enough evidence to charge you. This won't be the last time that Ms Jones gets herself into trouble, however (Pm:Quidditch).
Although the date printed on the fourth Daily Prophet Newsletter (DP4) is 1 October 1999, the timeframe for this event is 1992-1993.
From the Web
Writing by J K Rowling on Pottermore: The Daily Prophet
Pottermore feature: Quidditch collection