SNP turning away new members?

On several levels, this is a strange one:

With the Nationalists already trailing Labour in the polls for next year's crucial Scottish Parliament elections on the back of a disastrous Westminster campaign, party chiefs admitted that they had been forced to take action over the selection process.

Concerns appear to have been raised after a late flurry of new members, mostly with Asian names, was reported in the west of Scotland region. Many of the new members had previously been identified as Conservative voters and their membership fees of £12 each were paid for by just a handful of individuals.

After the alarm was raised by the East Dunbartonshire Council SNP group, the party's executive intervened to prevent anyone from voting in selection battles who had not been a member before 6 June this year.

So, if I am reading that correctly, no rules have been broken? Why then the panic? Also, if it is a deliberate attempt to subvert their selection process, it wasn't a very professional one and one which could be easily traced back. But again, what rules were broken? And why was it felt relevant to mention the fact that the new members mostly possessed "Asian names"?

But this has got to be the most bizarre part of the whole affair:

But yesterday Labour claimed that the SNP leadership's intervention on alleged vote-rigging was not enough, and that the party should launch an internal investigation to find out who was responsible.

Labour insisted the SNP needed to find which candidate was behind the attempt to rig the list vote and exclude them from standing for the party.

What's it got to do with Labour (particularly one itself with a less than sparkling record in this area) how another party selects its candidates?