The Premier League has sent a letter warning top-flight clubs to be vigilant about possible betting scams at academy level matches, BBC Sport understands. The League's general secretary Mike Foster revealed that suspected overseas betting syndicates have been receiving details of matches on mobile phones.

In one case, a man challenged at an under-18 match admitted he was working for an organisation in Hong Kong.

The Premier League says it wants to stamp out illegal betting. And it is asking clubs to look out for strangers who are constantly using mobile phones during play.