What does "leak over" mean?

From this excerpt:

"How the situation of Falun Gong practitioners in Hong Kong evolves in the coming months and how much of the repression leaks over from the mainland is a very important space to watch,"

I suppose it is a phrasal verb, but I couldn’t find any other occurrences of "leak over" as phrasal verb on the internet. All matches of those two words together are such that over functions as a simple preposition (not what I’m looking for), like below:

• Hackers leak over 20,000 unemployment applicants’ bank…
• Any leak over 2,000 square feet being prioritized for repair
• Labor demands Dutton shed more light on media leak over medevac bill

So is to leak over any different from simply to leak?

Thanks!