Regex testcase filtering: exception when hashmark is regex-quoted

i've been using regex to select which tests to run...and i've got some wierd exceptions when executing

mvn test "-Dtest=%regex[.*\Q#\E.*]"

executing the above command results in:

java.util.regex.PatternSyntaxException: 
Illegal/unsupported escape sequence near index 1
\E.*
 ^
	at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:364)
	at org.apache.maven.surefire.junit4.JUnit4Provider.executeWithRerun(JUnit4Provider.java:274)
	at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:238)
	at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:161)

i noticed earlier that maven might do some black-magic with these regexps in the background ( i know that it should know the class name earlier; to avoid starting testcases which will get entirely excluded...and thats cool )

...so..i assume maven does split the regex by the #; and that's okay - if that can't be avoided; place some pointers in the documentation about it and/or a more descriptive exception could be useful