mvn dependency tree not working

While building a sub-project where I am trying to find the jar dependency showing up in compliation which i am not able to locate in code/pom.
Tried command ;- mvn dependency:tree
this doesnt show up the dependency tree

this jar doesnt exist on nexus even, so i wanna see where is this defined in pom or dependency jar is calling it.

error is

Downloaded: http://IP:8081/nexus/content/groups/public-snapshots/abc/abc-web-utils/1.1-SNAPSHOT/maven-metadata.xml (351 B at 6.0 KB/sec)
Downloading: http://IP:8081/nexus/content/groups/public/org/hibernate/ehcache/hibernate-core/3.3.1.GA/hibernate-core-3.3.1.GA.pom
[WARNING] The POM for org.hibernate.ehcache:hibernate-core:jar:3.3.1.GA is missing, no dependency information available
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 6.065s
[INFO] Finished at: Tue Sep 20 16:29:32 IST 2011
[INFO] Final Memory: 8M/1009M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal on project com.abc.data.web: Could not resolve dependencies for project com.abc:com.abc.data.web:war:3.0.0.M1: Could not find artifact org.hibernate.ehcache:hibernate-core:jar:3.3.1.GA in abc (http://IP:8081/nexus/content/groups/public) -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/DependencyResolutionException
[kapila.narang@svn data-web]$ pwd
/home/kapilacvs/data-3.0/data-web/data-web

have made entry in pom also -
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.3</version>
</plugin>