Maven couldn't find LATEST version of a dependency

Question

It's only occurred to log4j,

My pom:

...
<dependency>
    <groupId>log4j</groupId>
    <artifactId>log4j</artifactId>
    <version>LATEST</version>
</dependency>

~m2/repository/log4j/log4j/maven-metadata-central.xml:

<?xml version="1.0" encoding="UTF-8"?>
<metadata>
  <groupId>log4j</groupId>
  <artifactId>log4j</artifactId>
  <version>1.2.15</version>
  <versioning>
    <release>1.2.16</release>
    <versions>
      <version>1.2.15</version>
      <version>1.2.16</version>
    </versions>
    <lastUpdated>20100331042604</lastUpdated>
  </versioning>
</metadata>

I can't figure out how does Maven find latest version, in maven-metadata-central.xml above, 1.2.16 is the latest version obviously.

BTW, the LATEST log4j dependency did work some time before, it's broken just recent.