I don't know much about the Amina Lone case, but the Biraderi system does exist and is a major issue in Pakistani communities due to the overwhelming majority (60-70%) of Pakistani families originating from Mirpur/Kashmir.
The low levels of political party members within many areas makes it possible to rig the system and nominate specific individuals to be the candidate running to be councillor. All you have to do is get your extended family and friends to join the political party and attend meetings on a regular basis, to make it seem legitimate that you are interested in politics, then when a vote comes along make sure they all know what they are doing. The main reason for getting involved in local politics is usually for local business interests, like building permits etc., but it can also be down to a need to control the political narrative of the 'Muslim/Pakistani Community'. The Biraderi systems is also influential in the running of mosques and maybe even the umbrella organisations like Muslim Council of Britain.
The article also mentioned the Gorton constituency which currently has Labour Shadow Cabinet member Afzal Khan as their MP. He is certainly someone who has benefited from the Biraderi system, and I know that for sure since one of my friends is the son of a Manchester Councillor who is quite close to Khan.http://www.manchestereveningnews.co.uk/news/local-news/labour-party-suspends-two-branches-688274
This article above doesn't mention the Biraderi system but I'm sure it had something to do with it, both Cheetham and Crumpsall are next to each other and have a massive Mirpuri/Kashmiri population. It is interesting that Richard Leese is mentioned alongside Khan in the article as he is currently the Manchester Labour Council Leader and he, despite apparently being a supporter of Amina Lone, dismissed her claims and reiterated the position that it was to do with her track record. http://www.manchestereveningnews.co.uk/news/greater-manchester-news/manchester-labour-party-hit-back-13570626
Whatever the reason for her dismissal it is certainly not a good sign for the Labour party and I expect it to get worse if the party doesn't deal with the Biraderi issue.